JPWO2014069551A1 - Sensor chip and measurement system - Google Patents

Abstract

With a disposable sensor chip, the sample is weighed with high accuracy without the risk of clogging the flow path. A sample is aspirated from the sample introduction port 3014 toward the fluid connection unit 3011, and then pressure is applied from the fluid connection unit 3011, and the introduced specified amount of sample is sent to the flow path having the measurement unit 3017 for measurement. .

Description

  The present invention relates to a measurement device for measuring a biological substance, a sensor chip incorporated in the measurement device, a measurement device using the same, and a measurement method.

  Laboratory tests are indispensable for understanding the health status of people and animals for early detection of illnesses and for analyzing the progress and causes of illnesses in patients. In the past, it was common for specialists in inspection rooms and inspection centers to perform inspections using large automatic analyzers. In recent years, point-of-care testing (POCT) in which a test is performed near a patient or at home has been spreading due to the development of a small and easy-to-use apparatus. The apparatus for POCT is roughly classified into a device for adding a sample to a film or membrane holding a dry reagent called dry chemistry, and a device for mixing a sample and a reagent using a flow path or a dispensing mechanism.

  In clinical examinations, a plurality of items are usually measured, so a device capable of measuring a plurality of items with high accuracy is required. Automatic analyzers have achieved this by accurately dispensing samples and mixing them with various reagents in sequence. In the apparatus for POCT, as with the automatic analyzer, the sample is automatically dispensed using the dispensing discharge mechanism and sequentially measured, or the user manually performs the sequential measurement.

WO 03/076937 A2 JP 10-123150 A

  The inventor has devised a small device for POCT that can perform precise measurement of multiple items without complicated operation by applying a disposable sensor chip having a flow path, and research and development. Went.

  For high-accuracy measurement, it is necessary to measure the sample with high accuracy, and in a disposable sensor chip, this is realized by filling the sample in a measuring part defined by a physical shape (Patent Document 1). However, there was concern about clogging of specimens in the bottleneck that is often used to define the physical shape. Furthermore, in order to measure a plurality of items, it is necessary to divide the specimen, for example, to perform measurement with high accuracy a plurality of times, and this clogging is further concerned.

  The sensor chip of the present invention has a plurality of fluid connection portions respectively connected to the plurality of device side fluid connection portions of a measurement device including a pressure adjusting mechanism and a plurality of device side fluid connection portions, and is combined with the measurement device. used.

  The sensor chip of the present invention is provided in the first flow path connecting the first fluid connection portion and the second fluid connection portion, the sample introduction port for introducing the sample, and the first flow channel. A second flow path connecting the first branch point and the sample introduction port; a second branch point of the first flow path provided at a position closer to the second fluid connection portion than the first branch point; And a third flow path connecting the third fluid connection portion, and the first flow path includes the first fluid connection portion and the first branch point or the first branch point and the first flow point. A sample detection unit is disposed between the two branch points, and a measurement unit that performs measurement on the sample introduced from the sample introduction port is disposed in the third flow path.

  The second flow path preferably includes a check valve or a filter between the sample introduction port and the first branch point. Moreover, it is preferable that the specimen detection unit includes an electrode.

  In addition, the sensor chip of the present invention has a waste liquid reservoir into which waste liquid is introduced, includes an electrode in the specimen detection unit and the measurement unit, and the substrate on which the electrode is formed is disposed on the substrate on which the waste liquid reservoir is formed. , A laminated structure in which the substrate on which the first channel, the second channel, and the third channel are formed is disposed on the substrate on which the electrode is formed. The waste liquid reservoir can be structured to be connected to the fifth fluid connection portion and the sixth fluid connection portion that are not connected to the first flow path. In this case, the waste liquid can be introduced into the waste liquid reservoir by connecting the second fluid connection part of the first flow path to the fifth fluid connection part via the flow path provided on the measuring device side. Alternatively, the waste liquid reservoir may be directly connected to the first flow path.

  The measuring device of the present invention is provided in the first flow path connecting the first fluid connection portion and the second fluid connection portion, the sample introduction port for introducing the sample, and the first flow channel. A second flow path connecting the first branch point and the sample introduction port; a second branch point of the first flow path provided at a position closer to the second fluid connection portion than the first branch point; The third flow path connecting the third fluid connection section, the pressure adjusting mechanism connected to the first flow path, the reagent introduction mechanism connected to the third fluid connection section, and the operation of each part of the apparatus A control unit for controlling, and the first flow path includes a specimen detection between the first fluid connection unit and the first branch point or between the first branch point and the second branch point. And a measurement unit for measuring the sample introduced from the sample introduction port is disposed in the third flow path, and the control unit controls the pressure control mechanism to control the sample. Aspiration into the first channel from the body introduction port toward the sample detection unit, and when the sample detection unit detects the sample, the suction by the pressure control mechanism is stopped, and then the pressure control mechanism is controlled to control the first The sample introduced into the flow path is transported to the third flow path, and then the reagent introduction mechanism is controlled to control the introduction of the reagent into the third flow path.

  As an example, the pressure control mechanism may be a suction / discharge pump connected to the first fluid connection. In this case, the control unit causes the suction / discharge pump to perform a suction operation to suck the sample into the first channel, and causes the suction / discharge pump to perform a discharge operation to discharge the sample into the third channel.

  In addition, the measurement method according to the present invention includes a step of sucking a sample into the first channel from a sample inlet connected to the first channel via the second channel, and the first channel. A step of stopping the aspiration and introducing a prescribed amount of the sample into the first flow path when the detected specimen detection unit detects the specimen, and applying a pressure to the first flow path to remove the prescribed amount of the sample from the first flow path. A step of introducing into a second flow path having a measurement unit connected to the flow path, a step of supplying a reagent to the measurement unit, and a step of measuring in the measurement unit.

  The sensor chip of the present invention includes a flow channel, a sample introduction port for introducing a sample into the flow channel, an electrode disposed in the flow channel, and a capture substance disposed upstream and downstream of the electrode. Features.

  As a capture substance, an antibody that recognizes a site common to non-glycated protein and glycated protein can be used. The glycated protein can be HbA1c or glycoalbumin. The sensor chip preferably includes a waste liquid reservoir connected to the flow path. Further, the sample introduction port can include a sample holding unit.

  Furthermore, the measuring method of glycated protein is disclosed. The measurement method consists of quantifying the glycation ratio of glycated protein in a sample by measuring the potential using an antibody that recognizes a site common to non-glycated protein and glycated protein and an enzyme-labeled antibody that recognizes the glycated portion. Features.

  Here, in the method for measuring glycated protein, the antibody is an immobilized antibody immobilized on a solid phase, a step of supplying a specimen to the solid phase, a step of binding a glycated protein in a sample solution to the immobilized antibody, Supplying an enzyme-labeled antibody to the solid phase, binding the enzyme-labeled antibody to the glycated protein bound to the antibody to form an immobilized antibody-glycated protein-enzyme-labeled antibody complex, supplying the substrate to the solid phase , Having a step of reacting a substrate with a complex enzyme to produce a reaction product, a step of measuring the concentration of the reaction product by measuring potential, and a step of converting the concentration of the reaction product into a glycated protein concentration in the sample solution it can.

  According to the present invention, the sample is measured using the sample detection unit provided on the flow path instead of the physical shape, so that the configuration of physically obstructing the sample such as a bottleneck is minimized, and the sample is accurately obtained. Because it can be measured, clogging can be prevented.

  Problems, configurations, and effects other than those described above will be clarified by the following description of embodiments.

Schematic which shows an example of a sensor chip. Schematic which shows an example of a measuring device and a sensor chip. The flowchart which shows an example of a measurement procedure. The figure which shows the state which set the sensor chip to the measuring apparatus. The figure which shows the example of the sample detection part comprised by the electrical detector. The figure which shows the example which has arrange | positioned the some sample detection part. The figure which shows the example of a measurement part. The schematic diagram which shows an example of the method of modifying the flow path of a sensor chip with an enzyme. Schematic which shows another example of arrangement | positioning of a sample detection part. Schematic which shows another example of a measuring device and a sensor chip. Schematic which shows an example of a sensor chip. Schematic which shows the other example of a sensor chip. The schematic diagram which shows the other example of a sensor chip. The schematic diagram which shows an example of the state which mounted | wore the measuring apparatus with the sensor chip. Schematic which shows an example of a measuring device and a sensor chip. The figure which showed the outline of the measurement of GA / albumin ratio. The figure which showed the outline of the procedure which measures GA / albumin ratio. The figure which showed that a fixed amount of human albumin could be capture | acquired by the anti-human albumin antibody fixed solid phase. The figure which showed that the GA / albumin ratio could be detected with a small dependence on the total albumin concentration. The figure which calculated theoretically the relationship between GA / albumin ratio and the density | concentration of GA and an anti- GA antibody complex. The figure which showed the method of correct | amending the amount of human albumins using an anti-human albumin antibody as a detection antibody. The figure which shows an example of the sensor chip for GA / albumin ratio measurement. The figure which shows an example of the apparatus for measuring with a sensor chip. The figure which shows the outline | summary of a glycoalbumin measuring kit. The figure which shows the external appearance of the apparatus for measuring with a sensor chip. The figure which shows an example of the measuring method using a sensor chip and an apparatus. The figure which shows the introduction method of the test substance to a sensor chip flow path. The figure which shows the electric potential measurement method using an electrochemical sensor. The figure which shows the example of the positional relationship of the electrode for electric potential measurement, and an antibody fixed part. The figure which shows an example of the measurement result of HbA1c / hemoglobin ratio.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a schematic view showing an example of a sensor chip of the present invention. The sensor chip 3001 performs measurement using a measurement device described later. The sensor chip 3001 includes fluid connection portions 3011, 3012, 3013 connected to the measurement device, a sample introduction port 3014 to which a sample is supplied, and a signal connection portion 3021 connected to the measurement device. Channels 3024, 3025, 3026, 3027, 3028, and 3029 are connected to the fluid connection portions 3011, 3012, 3013 and the sample introduction port 3014. Each flow path is connected at branch points 3022 and 3023. A sample holding unit 3016 is disposed in the flow path 3028 connected to the sample introduction port 3014. The sample holder 3016 may be disposed on the outside so as to contact the sample introduction port 3014. A measurement unit 3017 is disposed on the flow path of the sensor chip 3001, for example, the flow path 3026. A supplementary substance 3018 such as an antibody is disposed upstream and downstream of the measurement unit 3017. Preferably, the sensor chip 3001 has a waste liquid reservoir 3019. Preferably, a liquid absorber 3020 is disposed in the waste liquid reservoir 3019.

  FIG. 2 is a schematic diagram illustrating an example of the measurement device 101 and a sensor chip 102 that is used by being incorporated in the measurement device 101.

  The measuring apparatus 101 includes a control unit 111, a measuring unit 112, fluid connecting units 113, 114, 115, 116, 117, and a signal connecting unit 135. A suction / discharge pump 118 is connected to the fluid connection portion 113 by piping. Valves 119, 124, and 129 are connected to the fluid connection portions 114, 115, and 116, and the valves can be switched between “closed”, “open to atmosphere”, and “reagent supply”. When the valves 119, 124, and 129 are set to “reagent supply”, the fluid connection parts 114, 115, and 116 are pumps 120, 125, and 130 for supplying the first reagent 121, 126, and 131, or the second reagent 123. , 128, 133 are connected to pumps 122, 127, 132. A valve 134 is connected to the fluid connection portion 117, and the valve 134 is switched between “closed” and “atmospheric release”.

  The suction / discharge pump 118 and the valves 119, 124, 129, and 134 constitute a pressure adjusting mechanism. Valves 119, 124, 129, pumps 120, 125, 130, 122, 127, 132, first reagents 121, 126, 131, and second reagents 123, 128, 133 constitute a reagent supply mechanism.

  The sensor chip 102 includes a fluid inlet 141, 142, 143, 144, 145, a specimen inlet 146 to which a specimen is supplied, and a measuring device connected to the fluid connectors 113, 114, 115, 116, 117 of the measuring device 101. The signal connection unit 157 is connected to the signal connection unit 135. Fluid connection portions 141, 142, 143, 144, and 145 (the fluid connection portion 141 is the first fluid connection portion, the fluid connection portion 145 is the second connection portion, the fluid connection portion 142 is the third connection portion, and the fluid connection portion. 143 corresponds to the fourth fluid connection portion) and the sample introduction port 146 are connected to channels 171 to 180, and the arrival of the sample is detected on the channel 171 connected to the fluid connection portion 141. A specimen detection unit 147 is arranged. Here, the flow paths 171 to 176 connecting the fluid connection part 141 and the fluid connection part 145 are the first flow path, the branch point 161 is the first branch point, and the flow path connecting the sample introduction port 146 and the branch point 161. 177 is the second flow path, the branch point 162 is the second branch point, the flow path 178 connecting the fluid connection 142 and the branch point 162 is the third flow path, and the branch point 163 is the third branch point. In addition, the flow path 179 connecting the fluid connection portion 143 and the branch point 163 corresponds to a fourth flow path. In addition, on the flow path 178 that connects the fluid connection section 142 and the branch point 162, the sample detection section 149 and the measurement section 150 that detect the arrival of the sample are on the flow path 179 that connects the fluid connection section 143 and the branch point 163. The sample detection unit 151 and the measurement unit 152 that detect the arrival of the sample include the sample detection unit 153 and the measurement unit 154 that detect the arrival of the sample on the flow path 180 that connects the fluid connection unit 144 and the branch point 164. Has been placed. A check valve 148 is disposed on the flow path 177 connecting the sample introduction port 146 and the branch point 161. The sensor chip 102 has a waste liquid reservoir 155, and the position of the waste liquid reservoir 155 is not particularly limited. However, as an example in the sensor chip of FIG. 2, the waste liquid reservoir 155 has a flow path 175 whose one end is connected to the branch point 164. Further, the other end is connected to the fluid connection portion 145 by a flow path 176. Further, a flow path branched from these flow paths 175 and 176 may be provided, and a waste liquid reservoir may be connected to the branched flow path. In this case, the waste liquid reservoir may be a closed system, but a separate flow path may be provided to discharge the waste liquid. In the waste liquid reservoir 155, a liquid absorber 156 may be arranged as shown in FIG. The specimen detection units 147, 149, 151, 153 and the measurement units 150, 152, 154 are connected to the signal connection unit 157.

  In the vicinity of the measurement units 150, 152, and 154 of the channels 178 to 180, a probe corresponding to the measurement target in the sample, for example, an antibody is immobilized. The first reagents 121, 126, and 131 have a labeled probe corresponding to the measurement target, for example, an enzyme labeled antibody. The second reagents 123, 128, and 133 have a substance (substrate) that reacts with the label of the labeled probe. With these immobilized antibodies, enzyme-labeled antibodies, and substrates, a desired measurement target can be measured at each measurement unit by the same technique as enzyme-linked immunosorbent assay (ELISA).

  FIG. 3 is a flowchart showing an example of a measurement procedure using the measurement apparatus 101 and the sensor chip 102 shown in FIG. First, the user sets the sensor chip 102 to the measuring device 101 (S201). As a result, as shown in FIG. 4, the fluid connecting portions 113, 114, 115, 115, 117 of the measuring device 101 are connected to the fluid connecting portions 141, 142, 143, 144, 145 of the sensor chip 102, and the measuring device 101 The signal connection unit 135 is connected to the signal connection unit 157 of the sensor chip 102. Subsequently, the user sets a sample in the sample introduction port 146 (S202). The blood collection tube 401 is set in the sample introduction port 146 adapted to the blood collection tube.

  When measurement is started by a user's operation (S203), the subsequent operations are automatically performed based on instructions from the control unit 111 of the measurement apparatus 101 to each unit. The valves 119, 124, 129, and 134 are closed by an instruction from the control unit 111 (S204), and the suction / discharge pump 118 performs a suction operation (S205), so that the sample connects the sample introduction port 146 and the fluid connection unit 141. It is sucked into the channel 171. The control unit 111 can introduce the sample to the sample detection unit 147 by detecting that the sample has been aspirated to the sample detection unit 147 (S206) and stopping the suction / discharge pump 118 (S207).

  Next, when the valve 119 is opened in accordance with an instruction from the control unit 111 (S208) and a discharge operation is performed by the suction / discharge pump 118 (S209), the sample introduced into the flow path 171 by the function of the check valve 148 becomes the sample introduction port. The specimen introduced into the flow path 171 moves toward the fluid connection section 142 through the flow paths 172 and 178 that connect the fluid connection section 141 and the fluid connection section 142 because it cannot move to the 146 side. The amount of the specimen that moves at this time is defined by the capacity between the branching point 161 of the flow path 171 and the specimen detector 147. That is, the flow path between the branch point 161 of the flow path 171 and the sample detection unit 147 functions as a measurement unit that measures a specified amount of the sample. The specified amount of sample flows from the flow channel 171 through the branch point 162 through the flow channel 178, and the control unit 111 detects that the sample has reached the sample detection unit 149 (S210) and stops the suction / discharge pump 118. Thus (S211), a specified amount of sample can be transported to the sample detection unit 149. The valve 119 is closed by an instruction from the control unit 111 (S212), and the same is performed in the flow paths 179 and 180 connected to the fluid connection units 143 and 144 (S213), so that a predetermined amount of the sample detection units 151 and 153 can be obtained. The sample is transported.

  The control unit 111 waits for a specified time in order to cause the measurement target substance in the transported sample to react with the probes immobilized in the vicinity of the measurement units 150, 152, and 154 (S214). Next, the control unit 111 opens the valve 134 (S215), opens the valve 119 (S216), and supplies the first reagent 121 with the pump 120 (S217), so that the fluid connection unit 142 passes through the measurement unit 150. Then, the first reagent 121 is caused to flow into the waste liquid reservoir 155. The flow path 171 connecting the branch point 162 and the fluid connection portion 141 does not flow because the suction / discharge pump is connected to the fluid connection portion 141 side. As a result, analyte components other than the component bound to the probe immobilized in the vicinity of the measurement unit 150 are washed away, and the labeled probe included in the first reagent is supplied in the vicinity of the measurement unit 150. In addition, the sample component and the first reagent that have flowed into the waste liquid reservoir are absorbed by the liquid absorber 156.

  The control unit 111 closes the valve 119 (S218), and does the same in the flow paths 179 and 180 connected to the fluid connection units 143 and 144 (S219), so that the immobilized probe is also near the measurement units 152 and 154. The sample components that have not been bound to each other are washed and the labeled probes contained in the first reagents 126 and 131 are supplied. Since the control unit 111 reacts the labeled probe included in each of the supplied first reagents 121, 126, and 131 with the analyte component bound to the probe immobilized in the vicinity of the measurement units 150, 152, and 154, the control unit 111 Wait for time (S220).

  The control unit 111 opens the valve 119 again (S221), and supplies the second reagent 123 with the pump 122 in the same manner as the first reagent 121 (S222), so that the waste liquid passes through the measuring unit 150 from the fluid connection unit 142. The second reagent 121 is poured into the reservoir 155. Thereby, the unbound labeled probe is washed away, and the substrate contained in the second reagent is supplied in the vicinity of the measurement unit 150. Further, the first reagent and the second reagent are absorbed by the liquid absorber 156. Next, the control unit 111 closes the valve 119 (S223), and does the same in the flow paths 179 and 180 connected to the fluid connection units 143 and 144 (S224), so that the measurement unit 152 and 154 are not. The bound labeled probe is washed away and the substrate contained in the second reagent is supplied. The control unit 111 reacts the substrate contained in each of the supplied second reagents 123, 128, and 133 with the label of the immobilized probe-analyte component-labeled probe conjugate to generate a reaction product. Wait for time (S225).

  The control unit 111 measures the reaction product by each measurement unit 150, 152, 154 (S226), calculates the amount of the measurement target substance from the signal obtained by each measurement unit in the measurement unit 112 (S227), The result is communicated to the user by printing. The user removes the sensor chip 102 from the measuring apparatus 101 and discards it (S228).

  Thus, by controlling the pressure of the flow path using a pump or a valve based on the detection signal of the sample detection unit, a certain amount of sample can be metered and discharged with high accuracy multiple times. In addition, by providing a waste liquid reservoir in which the liquid absorber is arranged downstream of the measurement unit, it is possible to prevent back flow of liquid that is a concern when performing multiple measurements with the minimum necessary obstruction due to physical shape.

  In FIGS. 1 and 2, the sample introduction port is different from the fluid connection portion, but an existing or separately provided fluid connection portion can also be used as the sample introduction port.

  In the flowchart of FIG. 3, the case where two types of reagents are supplied has been described. However, the number of reagents may be one or three or more. A reagent may be held in the path. Moreover, although the measuring method using immunity was demonstrated, the measuring method using other chemical reactions, such as an enzyme, may be sufficient.

  In the configuration shown in FIG. 2, the following advantages can be obtained by performing the measurement according to the procedure shown in FIG. The mechanism can be simplified and the measuring apparatus can be made smaller compared to the case of using a dispensing discharge mechanism such as a pipetter for measuring the sample. Since the sample can be measured in a fine channel, the amount of the sample can be further reduced. By dividing the sample, not only measurement of a plurality of items but also comparison reference data can be acquired. Since the transport of the specimen is closed in the sensor chip, it is possible to reduce the risk of contamination due to the specimen and to reduce the measurement error due to carry-over. Since the sample is aspirated directly from the blood collection tube, it is possible to reduce the trouble of the user discharging the sample from the blood collection tube and the risk of contamination due to the sample scattering.

  For the specimen detection units 147, 149, 151, and 153, an optical detector, an electrical detector, a pressure detector, or the like can be used.

  Optical detectors include light sources such as halogen lamps, light-emitting diodes, and laser diodes, and optical elements such as slits and lenses, photomultiplier tubes, and light-receiving elements such as photodiodes. A difference in the amount of transmitted light is detected. The accuracy of specimen detection depends on the spot that is irradiated with light. For example, when a spot having a diameter of 0.8 mm is irradiated to a flow path having a depth of 100 μm and a width of 1 mm, the accuracy is about 0.08 μl obtained by multiplying the depth, width, and diameter.

  The measuring device may have a pressure detector. In FIG. 4, as an example, a pressure gauge 1601 that measures the pressure in the piping of the suction / discharge pump 118 and the fluid connection portion 113 is provided with a flow path as a bottleneck. When the sample is aspirated by the suction / discharge pump 118 and reaches the bottleneck part, the pressure changes by the pressure loss due to the bottleneck part. By detecting this pressure change with a pressure gauge, the arrival of the specimen is detected. As shown in step 209 of the flowchart, since the suction / discharge pump 118 performs a discharge operation thereafter, the sample is not intentionally sucked beyond the bottleneck. Therefore, the possibility of clogging that has been a concern in the measurement of specimens using a conventional bottleneck portion can be kept low. The accuracy of specimen detection depends on the length of the bottleneck required for pressure detection. For example, when pressure is detected in a 5 mm narrow passage in a flow path having a depth of 100 μm and a narrow passage width of 0.1 mm, the accuracy is about 0.05 μl obtained by multiplying the depth, width, and length of the narrow passage. Even in the case of using a configuration that physically obstructs the sample such as the bottleneck portion in this way, clogging can be prevented by adopting a configuration in which the sample does not pass through the bottleneck portion.

  As an electrical detector, an electrode, a power source, and an ammeter are combined to detect the difference in the amount of current flowing through the electrode depending on the presence or absence of the specimen. For example, as shown in FIG. 5, a pair of silver chloride electrodes are arranged on the flow path, and an AC power source and an ammeter are connected. FIG. 5A shows an example in which the electrodes 801 and 802 are arranged at different positions on the plane of the channel, and FIG. 5B shows an example in which the electrodes 803 and 804 are arranged so as to sandwich the channel. Is shown.

  When there is no specimen on the silver chloride electrode, almost no current flows. For example, when a specimen is introduced from the right side and contacts the specimen in the order of right and left silver-silver chloride electrodes, the silver-silver chloride electrode is electrically connected by the specimen when the left silver-silver chloride electrode contacts the specimen. , Current flows. When the specimen is ejected, the electrical connection between the silver and silver chloride electrodes is broken, and the current does not flow again. Therefore, multiple detections necessary for multiple measurements can be performed. In addition, since a small amount of specimen may remain on the electrode surface and the channel surface during ejection, current may flow between the silver and silver chloride electrodes due to the remaining specimen if the distance between the silver and silver chloride electrodes is short. is there. Since this causes a decrease in the accuracy of specimen detection, it is better to suppress this by separating the distance between the silver and silver chloride electrodes by about the width of the flow path. In addition to the silver chloride electrode, a noble metal electrode such as gold or platinum, or a carbon electrode may be used. The accuracy of analyte detection depends on the size of the electrode. For example, when an electrode of 0.5 mm × 0.5 mm is arranged in a flow path having a depth of 100 μm and a width of 1 mm, the accuracy is about 0.05 μl obtained by multiplying the depth, width, and electrode size.

  By arranging a plurality of specimen detection units side by side, the accuracy and speed of measurement can be improved. As shown in the flowchart of FIG. 3, the control unit 111 stops the suction by the suction / discharge pump 118 based on the detection of the sample by the sample detection unit 147 (S206) (S207). Due to the suction by the suction / discharge pump 118, the pressure in the flow path slightly decreases from the atmospheric pressure, and this serves as a driving force to suck the specimen. On the other hand, this decrease in pressure causes the air in the suction and discharge pump 118 and the air in the piping between the fluid connection 113 to expand. When the suction / discharge pump 118 stops, the pressure in the flow path becomes substantially equal to the atmospheric pressure, and the specimen suction stops. On the other hand, this pressure recovery causes contraction of the air in the suction / discharge pump 118 and the air expanded in the pipe between the fluid connection portion 113. Since the sample is aspirated by this contraction, there is a possibility that a slightly larger amount of the sample is aspirated than the prescribed amount. For example, when a specimen is aspirated by 2 mm more in a flow channel having a depth of 100 μm and a width of 1 mm, the specimen is weighed by 0.2 μl more than the specified amount. By suppressing the suction speed at the suction / discharge pump 118, it is possible to reduce a drop in the flow path pressure during suction and to suppress excessive suction of the specimen, but suppression of the suction speed increases the time required for measurement. End up.

  As shown in FIG. 6, by arranging a plurality of sample detectors 901 and 902 between the fluid connection part connected to the suction / discharge pump and the intersection 161 of the flow path, both the suction speed and the measurement accuracy can be made compatible. it can. The control unit 111 performs high-speed suction with the suction / discharge pump 118, and switches the suction by the suction / discharge pump 118 to low speed when the sample detection unit 902 near the sample introduction port 146 detects arrival of the sample. Then, the measurement is performed by detecting the sample in the sample detection unit 901 on the side far from the sample introduction port 146. Thereby, shortening of the measurement time by high-speed suction and high-precision measurement by low-speed suction can be made compatible. For example, if the distance between the specimen detection units 901 and 902 is 3 mm away, even if a specimen is aspirated 2 mm more after the specimen detection by the specimen detection part 902, the specimen detection of the specimen detection part 901 is performed at a low speed after that. Within the error range. Although FIG. 5 shows an example in which two sample detection units are provided and the effect of achieving both the suction speed and the measurement accuracy can be obtained, three or more sample detection units may be provided.

  As the check valve 148, filter paper can be used in addition to a general valve. At the time of sample aspiration (S205), a negative pressure is applied to the fluid connection part 141 and the fluid connection parts 142, 143, 144, and 145 are closed, so that the flow path is passed through the filter paper from the sample introduction port 146 that is the only opening. The sample is aspirated. On the other hand, when the specimen is discharged (S209), a positive pressure is applied to the fluid connecting portion 141, and the fluid connecting portion 142 is opened to the atmosphere. The sample is not pushed out to the sample introduction port 146 due to the pressure loss of the filter paper, and the measured sample is transported toward the fluid connection unit 142. Thus, the filter paper works in the same way as a check valve. When a blood cell separation filter is used as the filter paper, blood cells in the specimen can be removed when the whole blood sample is used as the specimen. A similar effect can be obtained by replacing the check valve with a bottleneck and increasing pressure loss. In that case, it is desirable to arrange a plurality of narrow flow paths in order to suppress clogging.

  Measurement units 150, 152, and 154 include an optical sensor such as an absorbance sensor, a light emission sensor, a fluorescence sensor, and a surface plasmon resonance (SPR) sensor, a physical sensor such as a quartz crystal microbalance (QCM) sensor, and current measurement (WO 03). / 076937 A2), electrochemical sensor such as potential difference measurement (Japanese Patent Laid-Open No. 2008-128803), ion sensitive field effect transistor (ISFET), ion selective electrode, and the like can be used.

  FIG. 7 is a diagram showing an example of these measurement units. FIG. 7A shows an example of an absorbance sensor. A portion denoted by reference numeral 1801 represents a sensor chip, and the other portions are optical systems (lenses, light receiving elements, etc.) built in the measuring apparatus. FIG. 7B shows an example of a light emitting sensor. A portion indicated by 1802 indicates a sensor chip, and the other portions are optical systems (lenses, light receiving elements, etc.) built in the measuring apparatus. FIG. 7C shows an example of the fluorescence sensor. A portion indicated by 1803 indicates a sensor chip, and the other portions are optical systems (lenses, light receiving elements, etc.) built in the measuring apparatus. FIG. 7D shows an example of the SPR sensor. A portion indicated by 1804 indicates a sensor chip, and the other portion is an optical system (lens, light receiving element, etc.) built in the measuring apparatus.

  FIG. 7E is a schematic diagram showing an example of a QCM sensor or an electrochemical sensor. The measurement unit is disposed in the sensor chip. Reference numeral 1805 denotes a sensor sensitive part such as an electrode, and 1806 denotes wiring connected to the sensor sensitive part. The wiring is electrically connected to a control unit built in the measuring device via the sensor chip and the connector of the measuring device. As can be seen by comparing these figures, in the case of a measurement unit connected by wiring such as a QCM sensor or an electrochemical sensor, the measurement unit and the measurement device only need to be electrically connected, so the sensor can be relatively freely used. The measuring part can be arranged in the chip.

  FIG. 8 is a schematic diagram showing an example of a method for modifying the flow path of the sensor chip with an enzyme or an antibody. As shown in FIG. 8A, electrodes 1401 and 1402 are arranged at the bottom of the flow path, and the opposite upper surface is modified with an enzyme or an antibody 1403. Thereby, an enzyme reaction or an immune reaction occurs on the upper surface of the flow path, and the result of the reaction can be measured by the electrodes 1401 and 1402. Further, as shown in FIG. 8B, a site different from the site where the electrodes 1401 and 1402 are arranged may be modified with an enzyme or an antibody 1403. In this case, after the reaction is caused at the site modified with the enzyme or antibody, the reaction solution is transported to the site where the electrode is arranged, and the measurement is preferably performed. For modification with enzymes and antibodies, physical adsorption, covalent bond, biotin-avidin bond, immobilize on beads such as latex beads, adsorb the beads, immobilize on magnetic beads, and then hold the magnetic beads using a magnet A method or the like can be used.

  FIG. 9 is a schematic diagram illustrating another arrangement example of the specimen detection units. In FIG. 2, the specimen detection unit 147 is arranged on the flow path connecting the fluid connection part 141 and the branch point 161, whereas in FIG. 9A, the specimen detection unit is placed on the flow path connecting the branch point 161 and the waste liquid reservoir 155. 147 is arranged. In this case, the suction from the fluid connection unit 145 is performed by using a suction pump as a pressure adjusting mechanism newly connected to the fluid connection unit 117 of the measuring device instead of the sample suction by the suction / discharge pump 118 in step 205 of the flowchart. Do. For example, the sample is aspirated as shown in FIG. In this case, the specimen detection unit 147 does not have a bottleneck part.

  In the flowchart shown in FIG. 3, the weighed specimens are introduced in the order of the measurement units 150, 152, and 154. However, in the first measurement and the second and subsequent measurements, a change in the channel wettability due to the adsorption of the sample component on the channel side surface is a main factor, and the measurement may be shifted. The first measurement can be prevented beforehand by throwing it into the waste liquid reservoir without introducing it into the flow path where the measuring section is arranged. Specifically, in place of steps 208 to 212 in the flowchart, the valve 134 is “open to atmosphere”, the suction discharge pump 118 discharges, and the valve 134 is “closed”. As a result, the sample weighed first is transferred to the waste liquid reservoir 155 and absorbed by the liquid absorber 156. Thereafter, steps 205 to 212 are repeated as usual.

  FIG. 10 is a schematic diagram illustrating another example of the measuring device 1101 and the sensor chip 1102. The difference from FIG. 2 is that, in the example of FIG. 2, the flow path in the sensor chip is connected to the waste liquid reservoir 155, but in the example of FIG. 10, the flow path in the sensor chip is the waste liquid reservoir. (Parts where the sample is measured and measured).

  The part of the sensor chip for measuring and measuring the sample is connected to the fluid connection part 1121 (corresponding to the second fluid connection part), and the valve connecting the fluid connection part 1111 and the fluid connection part 1112 of the measuring device is “open”. This leads to a fluid connection part 1122 (corresponding to a fifth fluid connection part) connected to the waste liquid reservoir. The discharged liquid is discharged into the waste liquid reservoir, and the air in the waste liquid reservoir is pushed out from the waste liquid reservoir through the vent 1123 (corresponding to the sixth fluid connection portion). The valve 1113 is set to “closed” when performing measurement or conveyance using the suction / discharge pump 118 and the sample detection unit 147. This cuts off the connection between the part where the sample is measured and measured and the waste liquid reservoir having a relatively large capacity, and suppresses the influence of the expansion and contraction of the air in the waste liquid reservoir caused by the pressure fluctuation by the suction / discharge pump 118, thereby improving the accuracy. Can be improved.

  Furthermore, the backflow of the waste liquid from the waste liquid reservoir can be suppressed by closing the valve 1113 except when the waste liquid is used. However, with the configuration as shown in FIG. 10, the specimen contacts the piping of the measuring apparatus. Unlike a disposable sensor chip, since the measuring device is used multiple times, contact of the sample with the piping of the measuring device can cause carryover of the substance to be measured. However, in the configuration shown in the example of FIG. 10, there is no part that performs measurement only with the waste liquid reservoir downstream of the pipe in contact with the specimen, so that there is almost no influence on carryover measurement in the apparatus pipe.

  FIG. 11 is a schematic diagram illustrating an example of a sensor chip. FIG. 11A is a schematic view of the sensor chip as viewed from above, and FIG. 11B is a schematic view of the sensor chip as viewed from the side. The sensor chip of this example has a structure in which three portions of an electrode substrate 1201, a flow path substrate 1202, and a waste liquid reservoir 1203 are stacked.

  The electrode substrate 1201 can be a glass epoxy resin printed circuit board, a plastic substrate embedded with a semiconductor chip, or the like. Electrode pairs 1211, 1212, 1213, 1214 for detecting a specimen and a silver electrode and silver serving as a measurement unit It has electrode pairs 1215, 1216, 1217 of silver chloride electrodes, and a connector electrode 1218 for connecting these electrodes to the measuring unit of the measuring device.

  For the flow path substrate 1202, plastic such as acrylic, vinyl chloride, polyethylene, polystyrene, polypropylene, and silicone rubber, glass, or the like is used. The flow path substrate 1202 has a flow path 1229, fluid connection parts 1219 to 1226 (the fluid connection part 1219 is the first fluid connection part, the fluid connection part 1226 is the second fluid connection part, and the fluid connection part 1220 is the third fluid connection part. The fluid connection portion, the fluid connection portion 1221 corresponds to the fourth fluid connection portion, the fluid connection portion 1225 corresponds to the fifth fluid connection portion, and the fluid connection portion 1224 corresponds to the sixth fluid connection portion). Have In this example, the fluid connection parts 1219 to 1226 have a tapered concave shape, which is compatible with the tapered and convex fluid connection part of the measuring device. A blood collection tube can be set at the sample introduction port 1227. The specimen is introduced into the flow path through the filter 1230.

  The waste liquid reservoir 1203 is also made of the same plastic as the flow path. A polymer absorber 1228 such as sodium polyacrylate is disposed in the waste liquid reservoir 1203, and the waste liquid introduced from the fluid introduction part 1225 is absorbed. Usually, the waste liquid is discharged from the fluid connection portion 1226 and introduced into the waste liquid reservoir 1203 of the sensor chip from the fluid connection portion 1225 through a pipe in the measuring device. Further, by introducing the waste liquid into the fluid connection part 1225, air is discharged from the fluid connection part 1224 connected to the waste liquid reservoir 1203. The fluid connection portion 1223 is not connected to the flow path in the sensor chip in the chip of this example. Instead of the polymer absorbent body 1228, a liquid water absorbent body such as a filter paper or a membrane may be used.

  By providing the waste liquid reservoir 1203 on the back surface of the electrode substrate 1201 separately from the channel for measuring and measuring the specimen, the following advantages can be obtained. When the sensor chip is set in the measuring device, the waste liquid reservoir is positioned vertically below the flow path, so that the possibility that the waste liquid flows back into the flow path is low. Even when the flow path is made as thin as about 100 μm for the purpose of reducing the amount of the sample, a sufficiently large waste liquid reservoir can be provided without depending on the thickness of the flow path. The flow path and the waste liquid reservoir can have a multilayer structure, and the sensor chip can be miniaturized. When the waste liquid reservoir is provided on the back surface of the electrode substrate, it is desirable to use an electrical measurement method for the measurement unit and the sample detection unit. This is because the waste liquid reservoir is on the back surface, and in the case of the optical detection method, measurement from the back surface becomes difficult.

  FIG. 12 is a schematic diagram illustrating another example of a sensor chip. FIG. 12A is a schematic view of the sensor chip as viewed from above, and FIG. 12B is a schematic view of the sensor chip as viewed from the side. The sensor chip of this example has a configuration in which three portions of an electrode substrate 1901, a flow path substrate 1902, and a waste liquid reservoir 1903 are stacked.

  As the electrode substrate 1901, a printed board of glass epoxy resin, a plastic substrate embedded with a semiconductor chip, or the like can be used. An electrode pair 1911, 1912, 1913, 1914 for detecting a specimen, a gold electrode serving as a measurement unit, It has electrode pairs 1915, 1916, 1917 of silver-silver chloride electrodes, and a connector electrode 1918 for connecting these electrodes to the measuring unit of the measuring device.

  A plastic substrate such as acrylic, vinyl chloride, polyethylene, polystyrene, polypropylene, or silicone rubber, glass, or the like is used for the flow path substrate 1902. The flow path substrate 1902 includes a flow path 1929, fluid connection portions 1919 to 1926 (the fluid connection portion 1919 is the first fluid connection portion, the fluid connection portion 1926 is the second fluid connection portion, and the fluid connection portion 1920 is the third fluid connection portion. (Corresponding to a fluid connection portion) and a sample introduction port 1927. In this example, the fluid connecting portions 1919 to 1926 have a tapered concave shape and are compatible with the tapered and convex fluid connecting portion of the measuring device. A blood collection tube can be set in the sample introduction port 1927. The specimen is introduced into the flow path through the filter 1931.

  The waste liquid reservoir 1903 is also made of the same plastic as the flow path. A polymer absorber 1928 such as sodium polyacrylate is disposed in the waste liquid reservoir 1903, and the waste liquid introduced from the through channel 1930 is absorbed. By introducing the waste liquid from the through channel 1930, air is discharged from the fluid connection portion 1926 connected to the waste liquid reservoir 1903. The fluid connection portions 1923 to 1925 are not connected to the flow path in the sensor chip in this chip. Instead of the polymer absorber 1928, a liquid water absorber such as filter paper or a membrane may be used.

  FIG. 13 is a schematic diagram illustrating another example of a sensor chip. FIG. 13A is a schematic plan view, and FIG. 13B is a schematic side view. The sensor chip of this example has a configuration similar to that of the sensor chip shown in FIG. 11, and is composed of three parts: an electrode substrate 1511, a channel substrate 1512, and a waste liquid reservoir 1513, but the method of introducing a sample is slightly different. In the example of FIG. 11, a blood collection tube is set at the sample introduction port 1227, whereas the sample is injected from the sample introduction port 1501 in the sensor chip of this example. When the sample to be injected is brought into contact with the sample introduction port 1501, the sample is introduced into the sample holding unit 1503 by the interfacial tension, and at the same time, air in the sample holding unit 1503 is pushed out from the air port 1502. After the sample is introduced into the sample holder, the sample is introduced into the flow path through the filter 1504 in the above-described procedure.

  FIG. 14 is a schematic diagram illustrating an example of a state in which a sensor chip is attached to the measurement apparatus. 14 (a) is an overall view, FIG. 14 (b) is an enlarged schematic view of the connection part of the sensor chip of the measuring device, FIG. 14 (c) is a perspective view of the fluid connection part of the sensor chip and the measuring device, and FIG. d) is a schematic cross-sectional view of the fluid connection part of the sensor chip and the measuring device.

  The sensor chip 1302 is set in the measuring device 1301, and the lid 1303 is closed. Then, the fluid connecting portion 1304 of the tapered convex measuring device and the fluid connecting portion 1305 of the tapered concave sensor chip are connected, and at the same time, the connector terminal 1306 of the measuring device and the connector electrode 1307 of the sensor chip are electrically connected. Connected. As shown in FIGS. 14C and 14D, the fluid connection portion has a tapered uneven shape so that the apparatus pipe and the sensor chip flow path are securely connected. At this time, the guide 1308 on the measuring device side is effective for alignment.

  Further, the reliability of the connection is improved by making the fluid connection portion 1304 of the measuring device hard plastic such as acrylic, polystyrene, or polyethylene and the fluid connection portion 1305 of the sensor chip made of soft plastic such as silicone rubber. Compared with the case where planes are connected using an O-ring, there are advantages that the contact area is improved, that some misalignment is automatically corrected, and that the dead volume of the connection portion can be reduced. Further, by sealing the fluid connection portion 1305 of the sensor chip with a thin film and breaking it by inserting the fluid connection portion 1304 of the convex measuring device, it is possible to prevent foreign matter from entering the flow path. Further, when the measurement is completed and the sensor chip is removed, the liquid adhering to the fluid connection portion is easily held by the concave shape on the sensor chip side, so that it is difficult to scatter before disposal.

  Of course, the unevenness relationship between the fluid connection portion of the measuring device and the sensor chip may be the reverse of the case of FIG. Consolidate the fluid connection parts on the same surface of the sensor chip, and make sure that one of the fluid connection part of the sensor chip and the fluid connection part of the measurement device is concave and the other is convex, so that the measurement device and sensor chip are securely connected. It is possible to drive the liquid in the sensor chip by controlling the pressure by a pump, a valve, or the like included in the measuring device with the minimum necessary obstruction due to the physical shape.

  FIG. 15 is a schematic diagram illustrating another example of the measurement device 2001 and the sensor chip 2002. The difference from FIG. 2 is that, in the example of FIG. 2, a waste liquid reservoir 155 is disposed on the flow path connecting the fluid connection portion 141 corresponding to the first fluid connection portion and the fluid connection portion 145 corresponding to the second fluid connection portion. On the other hand, in the example of FIG. 15, the flow path in the sensor chip is a flow path connecting the fluid connection portion 141 corresponding to the first fluid connection portion and the fluid connection portion 2021 corresponding to the second fluid connection portion. Is that the waste liquid reservoir is connected to the flow path 2024 branched at the branch point 2023 and further connected to another fluid connection portion 2022. The fluid connection parts 2021 and 2022 are respectively connected to the fluid connection parts 2011 and 2012 of the measuring device when in use. Valves 2013 and 2014 are connected to the flow paths connected to the fluid connection portions 2011 and 2012.

  The amount of glycated protein such as hemoglobin A1c (HbA1c) and glycoalbumin (GA) is a stable index reflecting long-term (several weeks to several months) blood glucose level, so blood glucose control for diagnosis and treatment of diabetes It is useful for determining the success or failure of Since the glycated protein is obtained by glycating a specific non-glycated protein such as hemoglobin or albumin according to the blood glucose level, the abundance ratio of the glycated protein per specific protein reflects a long-term blood glucose level. For example, in the case of HbA1c, the abundance ratio of HbA1c to hemoglobin (HbA1c / hemoglobin ratio), and in the case of GA, the abundance ratio of GA to albumin (GA / albumin ratio) is an indicator of long-term blood glucose level.

  In the present invention, when measuring and quantifying the proportion of glycated protein such as HbA1c or glycoalbumin, a characteristic pair can be used for the immobilized antibody and the enzyme-labeled antibody.

That is, in order to measure the ratio of glycated protein in a certain protein, an antibody that recognizes a site that does not depend on the presence or absence of glycation is used as an immobilized antibody, and an antibody that recognizes a glycated site is used as an enzyme-labeled antibody. In other words, an antibody that recognizes a site common to the glycated protein and the non-glycated protein is used as the immobilized antibody, and an antibody that recognizes the glycated portion of the glycated protein is used as the enzyme-labeled antibody. For example, when measuring HbA1c, an anti-Hb antibody can be used as the immobilized antibody, and an anti-HbA1c antibody can be used as the enzyme-labeled antibody. When measuring glycoalbumin, an anti-albumin antibody can be used as the immobilized antibody, and an anti-glycoalbumin antibody can be used as the enzyme-labeled antibody. The amount of the immobilized antibody is preferably more than the amount of the non-glycated protein and the glycated protein contained in the sample, for example, 1/10 equivalent or less with respect to the reference value of a healthy person.

  FIG. 16 illustrates a measurement example of the GA / albumin ratio used in the present invention. Anti-human albumin antibody 2102 is immobilized on solid phase 2101, and human albumin 2103 and GA 2104 in the sample solution are captured by anti-human albumin antibody 2102. Alkaline phosphatase (AP) -labeled anti-GA antibody (hereinafter, enzyme-labeled anti-GA antibody) 2105 recognizes and binds to the glycated site of GA2104 that has been captured (schematically represented by ◯ in FIG. 16). When the substrate 2106 is added, it is converted into the product 2107 by the labeling enzyme of the enzyme-labeled anti-GA antibody 2105 (in this case, alkaline phosphatase). The cases where the GA / albumin ratio in the sample solution is high and low are shown in FIGS. 16 (a) and 16 (b), respectively. The amount of GA2104 captured by the anti-human albumin antibody 2102 differs depending on the GA / albumin ratio, and the amount of the enzyme-labeled anti-GA antibody 2105 that binds changes accordingly. The ratio can be determined. Note that beads or the like may be used instead of the solid phase 2101 as long as the anti-human albumin antibody 2102 can be immobilized on the solid phase.

  FIG. 17 shows an outline of the procedure for measuring the GA / albumin ratio.

Step 1: Sample solution is added, and human albumin 2103 and GA 2104 in the sample solution are captured by anti-human albumin antibody 2102 immobilized on solid phase 2101. Step 2: Human in sample solution not bound to antibody by washing Step 3 except albumin 2103 and GA 2104: Enzyme-labeled anti-GA antibody 2105 is added and allowed to bind to GA 2104 captured by anti-human albumin antibody 2102. Step 4: Excess enzyme-labeled anti-GA antibody 2105 not bound by washing is removed. Exclude Step 5: Add substrate 2106 for alkaline phosphatase and measure enzyme activity from the amount of product 2107. At this time, in a general antigen-antibody reaction, an anti-human that is an excess of capture antibody than human albumin in the sample solution. Although albumin antibody is used, in the present invention, It is characterized by immobilizing an anti-human albumin antibody less than human albumin on a solid phase. Under the condition that the immobilization density of the anti-human albumin antibody is the same, if the human albumin concentration in the sample solution is higher than the concentration at which human albumin can bind to all of the anti-human albumin antibody, it is captured on the solid phase. The total amount of human albumin is the same as that of anti-human albumin antibody, and a constant amount of human albumin can be fractionated for each measurement. The concentration of the complex in the antigen-antibody reaction can be expressed by equation (1).
[Formula 1]

For example, Ab = 10 ⁻⁸ (M), k _on = 10 ⁵ (M ⁻¹ s ⁻¹ ), k _off = 10 ⁻⁴ (s ⁻¹ ), t _b = 10 (min), t _w = 1 ( min), X _b = 9.93 × 10 ⁻⁹ (M) when Ag = 10 ⁻⁶ (M), and X _b = 9.94 × 10 ⁻ when Ag = 10 ⁻⁵ (M). ⁹ (M).

Here, the antibody concentration Ab can be expressed by equation (2) using the antibody fixing density D, the reaction field volume V, and the antibody fixing area S in the reaction field.
[Formula 2]

From the equation (2), the conditions under which the anti-human albumin antibody was immobilized at a fixed density of 6.5 × 10 ⁻⁹ mol / m ² in a reaction field having a volume of 100 μl and an antibody immobilization area of 154 mm ² were as follows: antibody concentration 10 ⁻⁸ M It corresponds to. Since the human albumin concentration in blood is 5.6 to 7.4 × 10 ⁻⁴ M (37 to 49 mg / ml), the anti-human albumin antibody is immobilized at a fixed density of 6.5 × 10 ⁻⁹ mol / m ^2. For the reaction field (reaction field volume 100 μl, antibody immobilization area 154 mm ² ), the serum sample has an albumin concentration sufficient for human albumin to bind to all of the anti-human albumin antibodies on the solid phase.

The immobilization density of the anti-human albumin antibody is preferably 1.7 × 10 ^{−14 to} 3.6 × 10 ⁻⁴ mol / m ² . If the fixed density of the anti-human albumin antibody is lower than 1.7 × 10 ⁻¹⁴ , 3 significant digits of the measured value cannot be secured. Conversely, in the reaction field in which the anti-human albumin antibody is immobilized at a fixed density higher than 3.6 × 10 ⁻⁴ mol / m ² , depending on the performance of the antibody, all human albumin contained in the serum sample is anti-human albumin. Since it binds to the antibody, the total amount of human albumin captured on the solid phase varies depending on the concentration of human albumin in the serum sample, and a certain amount of human albumin cannot be captured for each measurement.

  FIG. 18 shows that by using the solid phase 2101 on which the anti-human albumin antibody 2102 is immobilized, a certain amount of human albumin can be captured by the antibody if the concentration of human albumin in the sample solution is a certain level or more. Detailed experimental procedures are shown below.

  A biotinylated monoclonal anti-human albumin antibody (capture antibody) was added to a microplate coated with streptavidin and immobilized. After washing with 0.1% Tween20-containing Tris Buffer Saline (hereinafter referred to as TBST), 2% bovine serum albumin (BSA) -containing TBST was added for blocking. The plate was washed with TBST to prepare an anti-human albumin antibody fixed plate.

  A dilution series prepared by mixing human albumin (containing GA) and TBST was prepared as a sample solution. The sample solution was introduced into the anti-human albumin antibody fixed plate, human albumin and GA in the sample solution were reacted with the capture antibody, and excess human albumin was washed with TBST. An alkaline phosphatase-modified monoclonal anti-human albumin antibody (detection antibody) was added to the plate and reacted, and then the excess antibody was washed with TBST.

  Bromochloroindolyl phosphate (BCIP), which is a chromogenic substrate for alkaline phosphatase, and a color former, nitro blue tetrazolium (NTB), were added and reacted, then ethylenediaminetetraacetic acid (EDTA) was added to stop the reaction, and 595 nm. The absorbance was measured. FIG. 17 shows the relationship between the human albumin concentration in the sample solution and the absorbance. The absorbance was almost constant at a human albumin concentration of 0.05 mg / ml or more, indicating that a certain amount of human albumin could be captured by the capture antibody.

  FIG. 19 is a diagram showing that the GA / albumin ratio can be measured with a small dependence on the total human albumin concentration by detecting GA contained in human albumin captured by the anti-human albumin antibody with the anti-GA antibody. It is. Detailed experimental procedures are shown below.

An anti-human albumin antibody fixed plate was prepared in the same manner as the measurement in FIG. A serum specimen having a known GA / albumin ratio and TBST were mixed to dilute the serum specimen 100-fold and 1000-fold to obtain a sample solution. At this time, the human albumin concentration in the sample solution is desirably equal to or higher than the concentration at which human albumin can bind to all of the immobilized anti-human albumin antibodies. That is, when the anti-human albumin antibody is immobilized at a fixed density of 6.5 × 10 ⁻⁹ mol / m ² in a reaction field having a volume of 100 μl and an antibody immobilization area of 154 mm ² , the dilution can be performed up to 5000 times.

The sample solution was introduced into the anti-human albumin antibody fixed plate, human albumin and GA in the sample solution were reacted with the anti-human albumin antibody, and the excess sample was washed with TBST. Monoclonal anti-GA antibody (detection antibody) modified with alkaline phosphatase was added, reacted with GA captured by anti-human albumin antibody, and then washed with TBST. In a general antigen-antibody reaction, the concentration of the detection antibody is about one-tenth that of the capture antibody. However, in the present invention, human albumin is captured by all of the anti-human albumin antibodies that are capture antibodies. The concentration of a certain anti-GA antibody is preferably higher than the concentration of the immobilized anti-human albumin antibody depending on the antibody performance. For example, if the fixed density of the anti-human albumin antibody is 2.1 × 10 ⁻⁸ mol / m ² , the reaction field volume is 100 μl, and the fixed area is 154 mm ² , the concentration of the anti-GA antibody should be 33 nM or more. . The anti-GA antibody may be a mixture of a plurality of types of monoclonal antibodies or may be a polyclonal antibody. Since there are multiple glycation sites of human albumin, sensitivity and reproducibility can be improved by mixing multiple types of monoclonal anti-GA antibodies with different epitopes.

The relationship between the density of the capture antibody and the concentration of the detection antibody can be generalized using the equations (1) and (2). As described above, if the human albumin concentration in the sample solution is equal to or higher than the concentration capable of binding to all of the anti-human albumin antibodies, the total amount of human albumin captured on the solid phase can be approximated by the number of molecules of the anti-human albumin antibodies. Therefore, by substituting the anti-human albumin antibody concentration Ab of the formula (2) into the human albumin concentration Ag captured by the antibody in the formula (1), the relationship between the density of the capture antibody and the concentration of the detection antibody can be expressed by one formula ( It can be expressed by 3).
[Formula 3]

  After BCIP and NTB were added and reacted, EDTA was added to stop the reaction, and the absorbance at 595 nm was measured. A graph summarizing the relationship between the GA / albumin ratio and the absorbance in the sample solution is shown in FIG. Although some background signal was added, absorbance corresponding to the GA / albumin ratio was obtained. According to the equation (3), the GA / albumin ratio and the GA / anti-GA antibody complex concentration theoretically have a linear relationship as shown in FIG. Also in FIG. 19, the relationship between the GA / albumin ratio and the absorbance can be expressed linearly, and the GA / albumin ratio could be measured according to the theory. Furthermore, there is no significant difference in absorbance between the 100-fold dilution and the 1000-fold dilution, and the GA / albumin ratio obtained from the calibration curve varies 1.1 to 1.4 times despite the 10-fold albumin concentration being different. I was able to suppress it. Since human albumin was captured using the immobilized anti-human albumin antibody, almost constant human albumin was captured despite the 10-fold difference in human albumin concentration. Therefore, even if there is a change in the dilution ratio when the specimen is diluted, the GA / albumin ratio can be measured while suppressing the influence of the change.

  In contrast to the example in which the specimen is diluted 100 times and 1000 times, the GA / albumin ratio in the specimen solution can be obtained in the same manner even at undiluted and low dilution ratios. However, in the case of undiluted or low dilution ratio, the measured value is likely to fluctuate due to non-specific adsorption of human albumin.

  As shown in FIG. 21, after detecting with an anti-GA antibody as shown in FIG. 21 (a), an enzyme-labeled anti-human albumin antibody 2108 recognizing an epitope different from the capture antibody is added, and FIG. By measuring the amount of human albumin captured by the immobilized anti-human albumin antibody in this way, even if the activity of the immobilized antibody fluctuates, the measured value with the anti-GA antibody is corrected to further suppress the fluctuation it can.

  After measuring the GA concentration of human albumin bound on a solid phase with an anti-GA antibody, and determining the total amount of human albumin with the anti-human albumin antibody and correcting the GA / albumin ratio, electrostatic interaction or hydrophobic interaction It can also be applied to normalization by adsorbing a certain amount of human albumin on a solid phase by physical adsorption such as action. Since there is a step of correcting the fluctuation of the total amount of human albumin due to physical adsorption, it can be measured with higher accuracy than the conventional method in which the total amount of human albumin is standardized by adsorption to a solid phase as in JP-A-2004-242522. .

  FIG. 22 is a diagram illustrating an example of a sensor chip for GA ratio measurement. 22A is a schematic plan view, and FIGS. 22B to 22D are schematic cross-sectional views. The sensor chip includes a solid phase 2701, a flow path portion 2702, and a liquid holding portion 2703. The solid phase 2701 includes solution introduction detection electrodes 2713 and 2714, a potential measurement electrode 2715, an antibody fixing site 2716, and terminals 2724 to 2726. The flow path portion 2702 has a sample introduction port 2712, reagent supply ports 2717, 2718, 2727, 2728, and a waste liquid reservoir connection port 2720. The liquid holding portion 2703 includes a sample holding portion 2711, a waste liquid reservoir 2719, and air. A hole 2721 and boundary portions 2722 and 2723 are provided. The positional relationship is explained by following the flow path from the reagent supply port 2717. The solution introduction detection electrode 2713, the antibody immobilization site 2716, the potential measurement electrode 2715, the antibody immobilization site 2716, and the solution introduction detection electrode 2714 flow in this order. It is provided inside the road. A sample introduction port 2712 is provided above the flow path between the antibody fixing site 2716 and the sample introduction detection electrode 2714. The approximate dimensions of the sensor chip were 20 mm x 10 mm, and the flow path was 1 mm wide x 13 mm long x 0.25 mm high.

  For the solid phase 2701, a semiconductor substrate such as silicon, a circuit substrate such as glass epoxy, or a film substrate such as polyethylene terephthalate (PET), polypropylene (PP), polycarbonate (PC), or polyimide (PI) is used. Can do. In the flow path portion 2702, a film in which polyethylene (PE), polyethylene terephthalate (PET), polypropylene (PP), polycarbonate (PC), polyimide (PI) or the like is laminated, ethylene vinyl acetate copolymer (EVA), or the like is used. A thermoplastic resin, an epoxy resin, or a silicone resin such as polydimethylsiloxane (PDMS) can be used. The liquid holding unit 2703 may be made of aramid fiber, glass fiber, cellulose fiber, nylon fiber, vinylon fiber, polyester fiber, polyolefin fiber, rayon fiber filter paper, nonwoven fabric or porous fiber. it can.

  The sample holder 2711 may be outside the sample inlet 2712 as shown in FIG. 22B, or may be between the sample inlet 2712 and the flow path as shown in FIG. It may be in the flow path as shown in FIG. In FIG. 22B and FIG. 22C, the specimen holding part 2711 separates the flow path from the outside, so that the pressure loss is large and it is not necessary to close the specimen inlet 2712 during measurement. For the boundary portions 2722 and 2723, low density polyethylene (LDPE) resin, ethylene vinyl acetate (EVA) resin, polyamide resin, or polyethylene terephthalate (PET) resin can be used. An antibody such as an anti-human albumin antibody is immobilized on the antibody immobilization site 2716. The immobilization method may be physical adsorption or chemical bonding. First, avidin is immobilized, and then a biotinylated antibody is immobilized. It may be immobilized by an avidin-biotin bond, or an antibody may be immobilized via avidin after immobilizing a biotin-modified molecule.

  FIG. 23 is a diagram showing an example of an apparatus for performing measurement with the sensor chip of FIG. FIG. 23A shows a top view of the positional relationship between the sensor chip 2801 and the device 2802, and FIG. 23B shows from the side the connection relationship between the reagent supply port and the electrodes / terminals of the sensor chip 2801 and the device 2802. Shown is a view. By setting the sensor chip 2801 in the device 2802, the reagent supply ports 2717, 2718, 2727, 2728 of the sensor chip 2801 and the reagent supply ports 2811, 2812, 2816, 2817 of the device 2802 are fluidly connected, and the sensor chip 2801 is connected. Terminals 2724 to 2726 and terminals 2813 to 2815 of the device 2802 are electrically connected. Antibody reagent solution 2826 is supplied to reagent supply port 2811 by pump 2825, sample dilution solution 2824 is supplied to reagent supply port 2812 by pump 2823, and cleaning solution 2828 is supplied to reagent supply port 2816 by pump 2827. Then, the substrate liquid 2822 is supplied to the reagent supply port 2817 by the pump 2821. The sample dilution liquid 2824 and the cleaning liquid 2828 may be solutions having the same composition. Further, the reagent supply ports may be provided at one to three locations, and a plurality of reagents may be supplied by branching a flow path connected to the reagent supply tank. An AC power source 2833 and an AC ammeter 2834 are connected to the terminals 2814 and 2815. A voltmeter 2832 is connected to the terminal 2813, and the other terminal of the voltmeter 2832 is connected to a reference electrode 2831 disposed in a flow path connected to the reagent supply port 2817. Control of the pumps 2821, 2323, 2825, and 2827 is performed by the control unit 2803, and control and measurement of the AC power source 2833, the AC ammeter 2834, and the voltmeter 2832 are performed by the measurement unit 2804. The apparatus 2802 includes a display unit 2805 for displaying measurement results and messages, and an input unit 2806 for a user to input an operation. The pumps 2821, 2323, 2825, and 2827 may be peristaltic pumps, syringe pumps, or diaphragm pumps. The reference electrode 2831 may be an internal liquid-type silver-silver chloride reference electrode, a bare silver-silver chloride electrode, or an ion-selective electrode as long as it exhibits a constant potential.

  FIG. 24 is a diagram showing an example of a glycoalbumin measurement kit. The glycoalbumin measurement kit 2901 of this example includes a solid phase 2701 provided with an antibody immobilization site 2716 on which an anti-albumin antibody is immobilized as shown in FIG. 22 and a potential measurement electrode 2715, and an antibody reagent solution 2826 as shown in FIG. It consists of the container which accommodated.

  FIG. 25 is a schematic diagram illustrating an example of a state in which a sensor chip is attached to the measurement apparatus. When the sensor chip 3002 is set in the measuring apparatus 3001 and the lid 3003 is closed, the sensor chip 3002 is connected to the reagent supply port and electrodes / terminals of the apparatus 3001.

  26 is a diagram illustrating an example of a measurement method using the sensor chip of FIG. 22 and the apparatus of FIG. A sample is added to the sample introduction port 2712 provided on the flow path (S2201). The specimen may be a body fluid collected from a biological sample itself, or may be subjected to pretreatment such as centrifugation, filtration, or dilution as necessary. The sample holding unit 2711 is made of an absorbent material such as filter paper. Further, since the periphery of the sample holding unit 2711 is surrounded by a boundary 2722, the added sample is held by the sample holding unit 2711. The sensor chip is set in the apparatus, and the sample diluent 2824 is introduced from the reagent supply port 2812 of the apparatus into the reagent supply port 2718 of the sensor chip using the pump 2823 (S2202). As the sample dilution solution, a buffer solution such as Tris Buffered Saline (hereinafter referred to as TBS) or Phospahte Buffered Saline (hereinafter referred to as PBS) is used. In order to introduce the sample diluent 2824 to the sample introduction port 2712, solution introduction detection electrodes 2713 and 2714 are used. For example, when an AC voltage is applied between the solution introduction detection electrodes 2713 and 2714 using an AC power source 2833, the current that was substantially zero before the sample diluent 2824 was introduced, and the sample diluent 2824 was introduced into the solution. When reaching the detection electrode 2714, the solution introduction detection electrodes 2713 and 2714 are electrically connected to increase. By monitoring this increase in current by the measuring unit 2804, it can be detected that the sample diluent 2824 has reached the solution introduction detection electrode 2714. If arrival of the sample diluent 2824 is detected by the solution introduction detection electrode 2714 (S2203), introduction of the sample diluent 2824 from the reagent supply port 2718 is stopped (S2204).

  When the sample holding unit 2711 and the sample diluent 2824 are kept in contact with each other for a certain time (S2205), the components in the sample held in the sample holding unit 2711 diffuse into the sample diluent 2824. Since the amount of the component in the specimen that diffuses into the specimen diluent 2824 depends on the retention time, the dilution ratio of the specimen can be controlled by the retention time. When a small amount of the sample diluent 2824 is aspirated from the reagent supply port 2718 and the components of the sample diffused in the sample diluent 2824 are conveyed to the antibody fixing site 2716 (S2206), human albumin in the sample is transferred to the antibody fixing site 2716. Captured by immobilized anti-human albumin antibody. After holding for a certain period of time, the sample dilution liquid 2824 including the sample is discarded into the waste liquid reservoir 2719 through the waste liquid reservoir connection port 2720 by introducing a sample dilution liquid from the reagent supply port 2718 (S2207). The flow path is washed with a washing liquid 2828 introduced from the reagent supply port 2727 (S2208), and human albumin not captured by the anti-human albumin antibody immobilized on the antibody immobilization site 2716 is removed. The cleaning liquid 2828 used for cleaning is also discarded in the waste liquid reservoir 2719.

  The antibody reagent solution 2826 is introduced from the reagent supply port 2811 of the apparatus into the reagent supply port 2717 of the sensor chip using the pump 2825 (S2209). As the antibody reagent solution 2826, a solution containing an alkaline phosphatase-labeled anti-GA antibody (labeled anti-GA antibody) or the like is used. Then, the labeled anti-GA antibody in the antibody reagent solution 2826 binds to GA captured by the anti-human albumin antibody. After holding for a certain period of time, a washing liquid 2828 is introduced from the reagent supply port 2718, and the flow path is washed (S2210), thereby removing unbound labeled anti-GA antibody. The antibody reagent solution 2826 and the cleaning solution 2828 are discarded in the waste solution reservoir 2719. The substrate liquid 2822 is introduced from the reagent supply port 2817 of the apparatus into the reagent supply port 2728 of the sensor chip using the pump 2821 (S2211). As the substrate solution, a solution containing ascorbic acid phosphate as a substrate of alkaline phosphatase and potassium ferricyanide as a mediator is used. The ascorbic acid phosphate in the substrate solution 2824 is hydrolyzed by alkaline phosphatase of the complex of anti-human albumin antibody-GA-labeled anti-GA antibody present at the antibody fixing site 2716, and the generated ascorbic acid reacts with potassium ferricyanide. Potassium ferrocyanide is generated, and the potential of the potential measuring electrode 2715 changes. Therefore, by measuring the potential difference between the potential measuring electrode 2715 and the reference electrode 2831 with the voltmeter 2832 (S2212), the amount of captured GA, that is, the GA / albumin ratio in the sample is obtained. In order to obtain the GA / albumin ratio with higher accuracy, a calibration curve representing the relationship between the GA / albumin ratio and the measured potential was prepared using a sample with a separately prepared sensor chip with a known GA / albumin ratio. May calculate the value of an unknown sample.

  With reference to FIG. 27, the details of the embodiment will be described with respect to the method for introducing the sample into the sensor chip channel in S2201 to S2206. FIG. 27 is an explanatory diagram showing details of a method for introducing the specimen into the sensor chip flow path. As Step 1, the specimen 3201 is dropped onto a specimen holding part 2711 made of a filter or the like provided in a part of the flow path. In step 2, a buffer solution 2824 is introduced into the flow path and is brought into contact with the sample holder 2711 and held for a certain period of time. In step 3, the components of the sample held in the sample holding unit 2711 diffuse into the buffer solution. By this operation, a diluted specimen solution equivalent to the case where the specimen is diluted with a buffer solution is obtained. The dilution rate of the diluted specimen solution can be controlled by the buffer retention time. Finally, in step 4, the diluted specimen solution is transferred to the antibody fixing site 2716, and antigen-antibody reaction is performed. Since the side where the buffer solution is introduced is upstream and the antibody fixing site 2716 is upstream of the sample holding unit 2711, the sample components diffused into the solution from the sample holding unit 2711 in the subsequent introduction of the solution in S2207 to S2212 Passing through the fixed portion 2716 can be suppressed.

  In FIG. 27, the side where the buffer solution is introduced may be upstream, and the antibody immobilization site 2716 may be downstream of the specimen holding unit 2711. The diluted sample solution can be transported to the antibody fixing site 2716 in the same procedure as in FIG. Since the antibody fixing part 2716 is downstream of the specimen holding part 2711, the specimen component diffused from the specimen holding part 2711 is supplied to the antibody fixing part 2716 even if the diluent is kept flowing. Therefore, instead of holding the diluent as in Steps 2 to 3, the diluent may be continuously fed, and in that case, the dilution factor of the diluted specimen solution supplied is controlled by the feeding speed.

  Since diffusion from a filter or the like is used for sample introduction, it is possible to suppress adsorption of non-specific sample components in the flow channel, which is a concern when introducing the sample into the flow channel, or in the flow channel. . Further, it is not necessary to measure a small amount of sample that can be a problem when realizing a high dilution factor of about 100 times. In addition, since the sample is held in the sample holding unit 2711 by the capillary force, scattering of the sample when the sensor chip is handled can be suppressed.

  The specimen holder 2711 can be made of aramid fiber, glass fiber, cellulose fiber, nylon fiber, vinylon fiber, polyester fiber, polyolefin fiber, rayon fiber filter paper, nonwoven fabric or porous fiber. . Alternatively, one or more pores can be used instead. By using these materials, it is possible to remove or reduce substances in the specimen that may cause clogging of the sensor chip flow path by the specimen holding portion 2711. In addition, by mixing activated carbon or hydrophobic resin with these materials, lipids or the like in the specimen that may be a factor of inhibition of the immune reaction system can be removed or reduced. At this time, it is desirable that these materials are substances having low reactivity to proteins and carbohydrates in order to prevent an extreme decrease in the abundance of human albumin and GA and fluctuations in the GA / albumin ratio.

With reference to FIG. 28, the details of the example of the potential measuring method using the electrochemical sensor in S2212 will be described below. In the detection step of the antigen-antibody reaction, the antigen-antibody reaction can be detected as an electrochemical signal by adding ascorbic acid phosphate, which is a substrate of the detection antibody-modifying enzyme alkaline phosphatase, and mediator, potassium ferricyanide. Ascorbic acid phosphate is hydrolyzed by alkaline phosphatase into ascorbic acid. Thereafter, dehydroascorbic acid is produced from ascorbic acid, and potassium ferricyanide is reduced to produce potassium ferrocyanide. As a result, the concentration ratio of the oxidizing substance and the reducing substance in the reaction solution changes and the potential of the reaction solution fluctuates. FIG. 28 (a) shows the measurement results of the potential that fluctuated with time due to the action of alkaline phosphatase present in the flow path. However, the potential does not fluctuate even if BSA, which is a negative control, is present instead of alkaline phosphatase. FIG. 28B is a graph in which the potential is converted into the concentration of potassium ferrocyanide generated using Nernst equation (4).
[Formula 4]

  A measurement result obtained by using an albumin / GA mixed sample having a predetermined GA / albumin abundance ratio is used for calibration, and a GA / albumin abundance ratio in the specimen is obtained from the measurement result of the specimen. As a measurement result to be used, an inflection point as shown in FIG. 28A can be used in addition to the produced potassium ferrocyanide concentration after a certain time and the amount of produced potassium ferrocyanide per unit time. This inflection point is an equivalent amount of potassium ferricyanide and potassium ferrocyanide according to equation (4). To obtain the potassium ferrocyanide concentration from the potential at an arbitrary time, the standard electrode potential is required, but at the inflection point, it always becomes the standard electrode potential. Therefore, the measurement using the inflection point is not affected by the fluctuation of the standard electrode potential that occurs at each measurement.

  Since the measurement sensitivity of the potential measurement method does not depend on the measurement volume, the measurement sample can be made smaller without affecting the measurement sensitivity compared to the oxidation-reduction current method and the spectrophotometry. In addition, since the potential measurement method obtains a signal proportional to the logarithm of the concentration of the enzyme-labeled antibody, a wider dynamic range can be obtained compared to the oxidation-reduction current method and the spectrophotometric method, which can obtain a signal proportional to the concentration of the enzyme-labeled antibody. It is done.

  The combination of antibody modifying enzyme for detection, its substrate and mediator is not limited to the combination of hydrolyzing enzyme and substrate such as alkaline phosphatase, ascorbic acid phosphate and potassium ferricyanide, but also oxidoreductase such as glucose oxidase and glucose and potassium ferricyanide. A combination of redox substances may also be used. The mediator concentration is preferably lower than the substrate concentration, and the measurement sensitivity can be adjusted by the concentration ratio of the substrate to the mediator.

  As the electrode 2715 for potential measurement, an electrode capable of electrochemical measurement is used, such as a noble metal such as gold or platinum, a carbon material such as graphite or carbon black, or a mixture of a carbon material and a noble metal. Unlike current measurement, where electrode area affects measurement current, potential measurement does not require precise adjustment of the electrode size.

  The relationship between the potential measurement electrode 2715 and the antibody fixing site 2716 will be described with reference to FIG. FIG. 29A shows the case where the antibody is immobilized only on the electrode, FIG. 29B shows the case where the antibody is immobilized over a wider range than the electrode including the electrode, and FIG. The case where the antibody is immobilized at a position sandwiched from the upstream and downstream directions of the flow channel with the electrode as the center without being immobilized is shown. Each graph shows the concentration of the reaction product when the substrate is added in the state where the immobilized antibody-antigen-enzyme labeled antibody complex is formed.

  The added substrate is decomposed by the enzyme of the complex of the immobilized antibody-antigen-enzyme labeled antibody to produce a reaction product, and spreads by diffusion. When the antibody is immobilized only on the electrode, the distribution of the reaction product has a concentration difference on the electrode as shown in FIG. In the example of this figure, the end of the electrode is about half of the center of the electrode. On the other hand, when the antibody is immobilized in a wider range than the electrode including the electrode, the concentration difference on the electrode is suppressed as shown in FIG. In addition, as shown in FIG. 29 (c), when the antibody is not fixed to the electrode and the antibody is fixed at the position sandwiched from the upstream and downstream directions of the flow path centering on the electrode, a slight concentration difference occurs on the electrode. However, the difference is 7% in this example, which is smaller than when the antibody is immobilized only on the electrode as shown in FIG. In the potential measurement, since the potential fluctuates according to the concentration of the reaction product, the antibody immobilization site 2716 of FIG. 29 (b) or FIG. 29 (c) is used so that the concentration of the reaction product on the electrode is constant. Thus, it is desirable to dispose the electrode so as to surround a wider area than the electrode. In addition, the antibody fixing site 2716 may be disposed so as to surround the electrode from four sides as shown in FIGS. 29D and 29E, and the antibody may be fixed on the electrode. It is desirable that the antibody immobilization site 2716 is adjacent to the electrode both when the electrode is sandwiched between the antibody immobilization sites and when the electrode is surrounded.

  FIG. 30 is a diagram showing that the HbA1c / hemoglobin ratio can be measured by detecting HbA1c contained in hemoglobin captured by the anti-hemoglobin antibody with the anti-HbA1c antibody. To a specimen with a known HbA1c / hemoglobin ratio, a surfactant such as dodecyltrimethylammonium boromide or sucrose monolaurate is added, and the β-chain N-terminal valine residue of hemoglobin, which is the recognition site of the anti-HbA1c antibody, is added. An exposed sample solution was prepared. Using this sample solution, measurement was performed in the same manner as in FIG. 19, and absorbance corresponding to the HbA1c / hemoglobin ratio in the sample solution as shown in FIG. 30 was obtained.

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. In addition, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

DESCRIPTION OF SYMBOLS 101 Measurement apparatus 102 Sensor chip 111 Control part 112 Measurement part 113-117 Fluid connection part 118 Suction / discharge pump 119,124,129,134 Valve 120,122,125,127,130,132 Pump 121,126,131 1st reagent 123, 128, 133 Second reagent 135 Signal connection portion 141, 142, 143, 144, 145 Fluid connection portion (141 First fluid connection portion, 145 Second fluid connection portion, 142 Third fluid connection portion, 143 Fourth fluid connection part)
146 Sample inlet 147, 149, 151, 153 Sample detector 150, 152, 154 Measuring unit 155 Waste liquid reservoir 156 Liquid absorber 157 Signal connection 161, 162, 163, 164 Branch point (161 First branch point, 162 2nd branch point, 163 3rd branch point)
171, 172, 173, 174, 175, 176, 177, 178, 179, 180 channel (171-176 first channel, 177 second channel, 178 third channel, 179 fourth channel Road)
401 Blood collection tubes 801, 802, 803, 804 Electrodes 1121, 1122 Fluid connection parts (1121 2nd fluid connection part, 1122 5th fluid connection part)
1123 Vent (sixth fluid connection)
1201 Electrode substrate 1202 Flow path substrate 1203 Waste liquid reservoir 1601 Pressure gauges 2021 and 2022 Fluid connection part (2021 2nd fluid connection part)
2023 Branching point 2024 Channel 2101 Solid phase 2102 Anti-human albumin antibody 2103 Human albumin 2104 GA
2105 Enzyme-modified anti-GA antibody 2106 Substrate 2107 Product 2108 Enzyme-modified anti-albumin antibody 2701 Solid phase 2702 Flow path portion 2703 Liquid holding portion 2711 Specimen holding portion 2712 Specimen inlet 2713, 714 Solution introduction detection electrode 2715 Potential measurement electrode 2716 Antibody Fixed portion 2717, 718, 727, 728 Reagent supply port 2719 Waste liquid reservoir 2720 Waste liquid reservoir connection port 2721 Air holes 2722, 2723 Boundaries 2724-2726 Terminal 2801 Sensor chip 2802 Device 2803 Control unit 2804 Measurement unit 2805 Display unit 2806 Input unit 2811 , 2812, 2816, 2817 Reagent supply ports 2813 to 2815 Terminals 2821, 2823 Pump 2822 Substrate liquid 2824 Specimen diluent 2825, 2827 Pump 2826 Antibody reagent liquid 2828 Washing Liquid 2831 Reference electrode 2832 Voltmeter 2833 AC power supply 2834 AC ammeter 2901 Glycoalbumin measurement kit 3001 Sensor chip 3011, 3012, 3013 Fluid connection part 3014 Specimen inlet 3016 Specimen holding part 3017 Measurement part 3019 Waste liquid reservoir 3020 Liquid absorber 3021 Signal Connection portion 3024, 3025, 3026, 3027, 3028, 3029 Channel 3022, 3023 Branch point 3201 Sample

Claims (25)

A flow path,
A sample inlet for introducing a sample into the flow path;
An electrode disposed in the flow path;
A sensor chip comprising a capture substance disposed upstream and downstream of the electrode. The sensor chip of claim 1,
The sensor chip, wherein the capture substance is an antibody that recognizes a site common to non-glycated protein and glycated protein. The sensor chip according to claim 2,
The sensor chip, wherein the glycated protein is HbA1c or glycoalbumin. The sensor chip according to claim 1,
A sensor chip comprising a waste liquid reservoir connected to the flow path. The sensor chip according to claim 1,
The sensor chip, wherein the sample introduction port includes a sample holding unit.   Saccharification characterized by quantifying the saccharification rate of glycated protein in a sample by potential measurement using an antibody that recognizes a site common to non-glycated protein and glycated protein and an enzyme-labeled antibody that recognizes the glycated portion Protein measurement method. The measurement method according to claim 6,
The antibody is an immobilized antibody immobilized on a solid phase, the step of supplying the specimen to the solid phase, the step of binding a glycated protein in the sample solution to the immobilized antibody, the enzyme on the solid phase Supplying a labeled antibody, binding the enzyme-labeled antibody to a glycated protein bound to the antibody to form an immobilized antibody-glycated protein-enzyme-labeled antibody complex, supplying a substrate to the solid phase, Reacting the substrate with the enzyme of the complex to produce a reaction product, measuring the concentration of the reaction product by measuring potential, and converting the concentration of the reaction product into a glycated protein concentration in a sample solution. A method for measuring a glycated protein characterized by comprising in order. In the measuring method according to claim 6 or 7,
The method for measuring a glycated protein, wherein the glycated protein is HbA1c or glycoalbumin. A first flow path connecting the first fluid connection and the second fluid connection;
A sample inlet for introducing the sample;
A second flow path connecting the first branch point provided in the first flow path and the sample inlet;
A third flow path connecting the second branch point of the first flow path and the third fluid connection section provided at a position closer to the second fluid connection section than the first branch point; Have
In the first flow path, a sample detection unit is disposed between the first fluid connection unit and the first branch point or between the first branch point and the second branch point. And
A sensor chip according to claim 3, wherein a measurement unit for measuring the sample introduced from the sample introduction port is disposed in the third flow path. The sensor chip according to claim 9, wherein
A sensor chip having a waste liquid reservoir. The sensor chip according to claim 10,
The sensor chip, wherein the waste liquid reservoir is located between the second branch point of the first flow path and the second fluid connection portion. The sensor chip according to claim 10,
A sensor chip, wherein a liquid absorber is disposed in the waste liquid reservoir.   The sensor chip according to claim 9 or 10, further comprising a plurality of fluid connection portions. The sensor chip according to claim 9, wherein
The sensor chip, wherein the second flow path includes a check valve or a filter between the sample introduction port and the first branch point. The sensor chip according to claim 9, wherein
A sensor chip, wherein the specimen detection unit includes an electrode. The sensor chip according to claim 9, wherein
In the first flow path, a plurality of specimen detection units are provided between the first fluid connection unit and the first branch point or between the first branch point and the second branch point. A sensor chip which is arranged. The sensor chip according to claim 9, wherein
A fourth flow path connecting the third branch point of the first flow path and the fourth fluid connection section provided at a position closer to the second fluid connection section than the second branch point. Have
The sensor chip according to claim 4, wherein a measurement unit for measuring the sample introduced from the sample introduction port is disposed in the fourth flow path. The sensor chip according to claim 9, wherein
The sensor chip, wherein the measurement unit includes a sample detection unit. The sensor chip according to claim 9, wherein
A waste fluid reservoir having a fifth fluid connection portion and a sixth fluid connection portion that are not connected to the first flow path, and connected to the fifth fluid connection portion and the sixth fluid connection portion; A sensor chip. The sensor chip according to claim 9, wherein
A waste liquid reservoir into which the waste liquid is introduced;
The sample detection unit and the measurement unit include electrodes,
A substrate on which the electrode is formed is disposed on the substrate on which the waste liquid reservoir is formed, and the first flow path, the second flow path, and the third flow path are disposed on the substrate on which the electrode is formed. A sensor chip having a laminated structure in which a substrate on which a channel is formed is disposed. The sensor chip according to claim 20,
The sensor chip, wherein the waste liquid reservoir is connected to a fifth fluid connection portion and a sixth fluid connection portion that are not connected to the first flow path. The sensor chip according to claim 20,
The sensor chip, wherein the waste liquid reservoir is connected to the first flow path. A first flow path connecting the first fluid connection and the second fluid connection;
A sample inlet for introducing the sample;
A second flow path connecting the first branch point provided in the first flow path and the sample inlet;
A third flow path connecting a second branch point of the first flow path and a third fluid connection portion provided at a position closer to the second fluid connection portion than the first branch point;
A pressure adjusting mechanism connected to the first flow path;
A reagent introduction mechanism connected to the third fluid connection;
A control unit for controlling the operation of each part of the device,
In the first flow path, a sample detection unit is disposed between the first fluid connection unit and the first branch point or between the first branch point and the second branch point. And
In the third flow path, a measurement unit for measuring the sample introduced from the sample introduction port is disposed,
The control unit controls the pressure control mechanism to suck the sample from the sample introduction port toward the sample detection unit into the first flow path, and the pressure is detected when the sample detection unit detects the sample. The suction by the control mechanism is stopped, and then the pressure control mechanism is controlled to transport the sample introduced into the first channel to the third channel, and then the reagent introduction mechanism is controlled. A measuring apparatus for introducing a reagent into the third flow path. The measuring device according to claim 23,
The pressure control mechanism is a suction / discharge pump connected to the first fluid connection;
The controller causes the suction / discharge pump to perform a suction operation to suck the sample into the first channel, and causes the suction / discharge pump to perform a discharge operation to discharge the sample into the third channel. A measuring device. A step of aspirating a sample into the first channel from a sample inlet connected to the first channel via a second channel;
A step of stopping aspiration when a sample detection unit provided in the first channel detects a sample and introducing a specified amount of sample into the first channel;
Applying a pressure to the first flow path to introduce the specified amount of the sample into a second flow path having a measurement unit connected to the first flow path;
Supplying a reagent to the measuring unit;
A step of measuring in the measuring unit;
A measuring method characterized by comprising:

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