JP4958622B2 - Sample analysis system and sample transport method - Google Patents

Description

  The present invention relates to an analyzer for detecting the amount of a component contained in a sample, and relates to a technique for handling a sample, a reagent, or the like as a droplet in order to analyze with a very small amount of sample.

  As an analyzer for detecting the amount of components contained in a sample, the sample solution is irradiated with white light from a halogen lamp, etc., and the light transmitted through the sample solution is dispersed by a diffraction grating to extract the necessary wavelength component. Spectroscopic analyzers that measure the amount of a target component by determining the absorbance are widely used. Alternatively, the sample solution may be irradiated after white light is separated by a diffraction grating. Conventionally, in these analyzers, a sample and a reagent are dispensed into a plastic or glass reaction container, and these components are mixed to irradiate light into a sample solution to measure the amount of components.

  However, in recent years, in order to reduce reagent costs and reduce the burden on the environment, it has been required to use a small amount of sample solution for analysis, and it has become difficult to handle liquids by using a small amount of sample solution in the conventional method. There is also a problem that accurate measurement cannot be performed due to bubbles generated during mixing. Therefore, a method is considered in which a very small amount of liquid is circulated by some method, and the component amount of the liquid is measured during the distribution.

  As a first method for distributing a very small amount of liquid, there is a method in which the liquid on the electrode formed on the substrate is distributed by electrical control. The following two methods are generally known for this method.

  In the first method, which is distributed by electrical control, the liquid flowing between two opposing substrates on which a plurality of electrodes are formed is sandwiched in a granular form, and a voltage is applied to the electrodes between the two opposing substrates. Therefore, this is a system for driving a granular liquid (Japanese Patent Laid-Open No. 59-206868). In this system, usually, a large number of electrodes are formed along a liquid flow path through which a liquid flows on one substrate, and one electrode connected to the ground is provided on the other substrate. The shape of each of a large number of electrodes is generally rectangular or triangular. When a voltage is applied to one of the electrodes below the granular liquid while the granular liquid is standing across several electrodes, electrocapillary phenomenon (MG Lippmann, Ann. Chim. Phys. 5, 494 1875 ), The wettability of the granular liquid on the electrode to which the voltage is applied is attracted to the electrode, and the granular liquid finally moves directly above the electrode to which the voltage is applied. To do. This is repeated and distributed.

  As another method of distributing by electric control, the liquid flowing on one substrate having a number of electrodes having the same shape as described above is supplied in a granular form, and a voltage is applied to the electrodes near the granular liquid. There is a system in which granular liquid is driven by applying a voltage (Japanese Patent Laid-Open No. 10-267801). A large number of electrodes are arranged along a liquid flow path through which a granular liquid flows. An electric field is formed between the electrode existing in the lower part of the liquid and the electrode near the liquid, and driven by using the force of the electric field. This is repeated and distributed.

  Both of these systems can circulate a minute amount of liquid. It is also possible to mix two minute amounts of granular liquid by circulating them on the same electrode, and it is also possible to divide one minute amount of granular liquid into two. The two methods described above are the same in that a force for driving a liquid is generated by applying a voltage. In the present invention, the driving force of the liquid used in both methods is called an electrostatic force.

  The advantage of a system that circulates and analyzes granular liquids using electrostatic force is that bubbles are used because a single or two substrates are used, compared to a method using a plastic or glass reaction vessel surrounded by a wall. Designate where to place granular liquid by applying voltage and applying voltage to electrode so that many granular liquids can be driven independently at any place in the substrate. Therefore, it is easy to measure the timing of when the sample, reagent or sample solution reaches the measurement unit.

  As a second method for distributing a very small amount of liquid, there is a method using a surface acoustic wave as disclosed in JP-A-2005-257407. In this method, an electrode part serving as a surface acoustic wave generating part is provided on a piezoelectric material such as lead zirconate titanate (PZT) capable of propagating surface acoustic waves, and the surface acoustic wave generated by the surface acoustic wave generating part is used to form particles. A micro liquid is distributed. In this method, if the part that wants to circulate a small amount of liquid is a piezoelectric body, it is only necessary to have one electrode part as a surface acoustic wave generating part, which is as complicated as the above-mentioned method of circulating a minute liquid by electrostatic force. There is a feature that no electrode arrangement is required.

  As a third method of circulating a small amount of liquid, a tube or a narrow tube filled with a medium is used, pressure is applied to the medium, the flow is made through the narrow tube, a small amount of sample solution is placed in the medium, and the medium There is a method of propagating the sample solution by the flow of the liquid (Japanese Patent Laid-Open No. 2003-20041, US Pat. No. 4,259,291). In this method of propagating the sample solution by the flow of the medium, the transported micro liquid is less likely to be adsorbed on the inner wall surface of the thin tube than in the example using electrostatic force or the example using surface acoustic wave. The reason is that the medium flows along with the micro liquid in the narrow tube, so there is a difference in flow velocity between the inner wall of the narrow tube and the center of the narrow tube, and the medium film is maintained near the wall. This is because, as in the case of using an electrostatic force, a force for adsorbing a minute liquid to the wall surface is not generated by the electrostatic force.

JP 59-206868 Japanese Patent Laid-Open No. 10-267801 JP 2005-257407 A JP2003-20041 U.S. Pat.No. 4,259,291 M. G. Lippmann, Ann. Chim. Phys. 5, 494 1875

  There are many problems in transporting a small amount of liquid. In the circulation of liquids using electrostatic force, there are liquids that cannot be transported due to differences in liquidity. For example, a liquid containing a large amount of protein such as albumin is easily adsorbed on the substrate, and once adsorbed, it cannot be moved by electrostatic force. Also, liquids containing a large amount of surfactant are difficult to move. In the method of transporting using surface acoustic waves, since the substrate surface pushes and moves micro liquids by surface elastic waves, liquids containing a large amount of proteins such as albumin are easily adsorbed to the substrate as in the case of micro liquid flow by electrostatic force. When adsorbing, it cannot be transported. In the method using a tube or narrow tube packed with a medium inside, when the flow in the narrow tube stops for a certain time or longer, the sample solution still contacts the wall inside the narrow tube. If a flow is generated, a minute liquid can be forcibly moved, but adhesion remains on the inner wall of the narrow tube. If the inner wall of the narrow tube is treated with water repellency, even if the flow in the narrow tube stops for a certain period of time, it can be prevented from adhering to water-soluble liquids. If it is adsorbed on the wall surface, even if it is forcibly transported, a part of the liquid remains attached to the wall surface inside the narrow tube.

  As described above, the prior art has a problem in that it cannot be transported or adsorption remains due to the difference in liquid properties of the micro liquid to be transported. In particular, a liquid containing a large amount of protein such as albumin is easily adsorbed to the substrate, and if adsorbed, it cannot be transported, or even if it is transported, a part of the liquid remains attached to the wall surface.

  In the present invention, a micro liquid containing a large amount of protein such as albumin is transferred to a substrate in a method of transporting a liquid using electrostatic force or using surface acoustic waves, and to a wall surface in a method of propagating a sample solution by a medium flow. The objective is to provide a liquid analysis system that prevents adsorption and accurately transports micro liquids, which were difficult to transport in the past, and enables stable analysis with a small amount of sample.

  In the present invention, the above object is achieved by adding a surfactant to the liquid transported between two substrates arranged in parallel. The addition concentration of the surfactant is preferably about the critical micelle concentration. The sample liquid may be transferred by any of electrostatic force transfer, ultrasonic transfer, and transfer by the flow of the transfer medium.

  According to the present invention, when a sample, a reagent, or the like is handled as a droplet for analysis with a very small amount of sample, the adsorption of the droplet is prevented and the stable analysis with a very small amount of sample is achieved by stably transporting the droplet. Is possible.

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

  A liquid analysis system according to the present invention will be described with reference to FIGS. In this embodiment, an example in which electrostatic force conveyance is used for conveyance of a sample and a reagent will be described.

  First, the configuration of the liquid analysis system in this embodiment will be described with reference to FIGS. 1, 2, and 3. FIG. 1 and 2 are schematic views showing the configuration of the liquid analysis system. FIG. 1 is a plan view of the apparatus, FIG. 2 is a sectional view of the apparatus, and FIG. 3 is a sample cassette portion for holding a plurality of tubes containing samples. Shown in cross section.

  The liquid analysis system in this embodiment is mainly composed of a sample cassette loading / conveying section 1, a sample cassette 2, a stirring mechanism 3, a sample dispenser cleaning mechanism 4, a sample dispenser 5, a sample adjustment disk 6, a surfactant tank 7, A sample adjusting unit 10 including a surfactant dispenser 8 and a cleaning mechanism 9, an adjusted sample charging dispenser 11, an adjusted sample charging dispenser cleaning mechanism 12, a sample transport device 13, a reagent charging unit 14, a measuring unit 15, and a reagent charging The unit 14 ′, the measurement unit 15 ′, and the sample transport measurement unit 17 including the waste liquid recovery unit 16 are configured. As shown in FIG. 3, a plurality of sample tubes 19 containing the sample 18 are set in the sample cassette 2, and similarly, a sample adjustment tube for mixing the sample 18 and the surfactant 21 on the sample adjustment disk 6. A plurality of 20 are set. The surfactant tank 7 contains a surfactant 21 or a dilute solution 21 ′ containing a surfactant. Similarly, in the reagent charging sections 14 and 14 ′, a specific reaction is performed by adding and mixing to the adjusted sample. There are reagents 22 and 22 'for waking up.

  Next, the configuration of the sample transport measurement unit 17 will be described in detail with reference to FIGS. 4, 5, 6, and 7. FIG. 4 is a diagram in which only the sample transport measurement unit is extracted, and a plan view is partially shown in section. FIG. 5 is a sectional view of FIG. 4 as viewed from the front. 6 and 7 show partially enlarged views of FIG.

  As shown in FIGS. 4 and 5, the sample transport measurement unit 17 includes a first substrate 30 made of transparent glass, ceramic, or resin, and a second substrate made of a similar material arranged in parallel with the first substrate 30. 31 and a spacer 32 that keeps the first substrate 30 and the second substrate 31 parallel and at a constant distance. Between the first substrate 30 and the second substrate 31, a silicone or fluorine-based oil is used as a carrier medium. 33 is satisfied.

  On the first substrate 30, a plurality of first electrodes 34 made of a conductive thin film are arranged on the side facing the second substrate 31 so as to be a plurality of transport paths for the adjustment sample and the reagents 22, 22 ′. The surface of the electrode 34 is covered with an insulating film 35, and the surface on the side facing the second substrate 31 is subjected to water repellent treatment. Since the first electrode 34 and the insulating film 35 are very thin and cannot be written even if enlarged, in the figure, the thickness direction is exaggerated as shown in FIG. Each of the first electrodes 34 is wired by an AC rectangular wave power source 51 and a switch 44 as shown in FIG. 7 and FIG.

  On the second substrate 31, the second electrode 36 is disposed on the entire surface facing the first substrate 30 or in a range covering at least a portion facing the first electrode 34. Further, the surface on the side facing the first substrate 30 is subjected to water repellent treatment. Note that the insulating film 37 is not always necessary, and the surface on the side facing the first substrate 30 may be water-repellent.

  In the second substrate 31, a sample introduction port 38 for introducing the adjustment sample into the sample transport measurement unit 17, a reagent introduction port 39, 39 'for introducing the reagent 22, 22', and a waste solution for taking out the sample after the analysis as a waste solution The collection port 40 is provided in a state where it rises in a cylindrical shape. The sample introduction port 38, the reagent introduction ports 39 and 39 ', and the waste liquid collection port 40 are arranged at positions that overlap the electrode 34 when viewed from the plane.

  As described above, the spacer 32 seals between the first substrate 30 and the second substrate 31 in order to keep the first substrate 30 and the second substrate 31 parallel and at a constant distance, and holds the oil 33 therebetween. Provided for. In that case, if any of the sample introduction port 38, the reagent introduction ports 39 and 39 ', and the waste liquid collection port 40 is an oil introduction portion, air is pushed out from another port and filled with oil. It is desirable that the oil contact part should be water-repellent in preparation for unforeseen circumstances such as the sample or reagent coming off the transport path. The method of filling the oil 33 between the first substrate 30 and the second substrate 31 can be performed by immersing the first substrate 30 and the second substrate 31 in a tank filled with the oil 33 without sealing with the spacer 32. is there. In that case, the gap between the first substrate 30 and the second substrate 31 serves as an oil introduction portion, and air is pushed out from any of the sample introduction port 38, the reagent introduction ports 39 and 39 ′, and the waste liquid collection port 40, and the oil It is filled. In this case as well, it is desirable to perform a water-repellent treatment on the part where the oil comes into contact in preparation for an unexpected situation such as the sample or reagent coming off the conveyance path.

  Next, an analysis method using the liquid analysis system in this embodiment will be described with reference to FIGS. 1 to 3 and FIGS. 6 to 10. FIG. 1 and 2, first, a sample solution to be analyzed is put into a sample tube 19 as a sample 18 for each target, mounted in the sample cassette 2, and loaded into the sample cassette loading and conveying section 1 of the liquid analysis system. .

  When the analysis operation is started, the liquid analysis system first performs an operation for sample preparation. First, the surfactant dispenser 8 sucks the surfactant 21 or the diluent 21 ′ containing the surfactant in the surfactant tank 7 and sucks the surfactant 21 or the diluent 21 containing the surfactant. 'Is discharged into the sample adjusting tube 20 set on the sample adjusting disk 6. At the same time, the sample cassette 2 loaded in the sample cassette loading / conveying section 1 moves so that the sample tube 19 containing the desired sample 18 comes to a position where the sample dispenser 5 can be sucked. A certain amount is aspirated. Subsequently, when the sample adjusting disk 6 rotates and the sample adjusting tube 20 from which the surfactant 21 or the diluent 21 ′ containing the surfactant is discharged moves to the discharge position of the sample dispenser 5, the sample dispenser 5 causes the sample to be sampled. 18 is discharged into the sample adjusting tube 20 by a certain amount. Here, the sample adjusting tube 20 contains a fixed amount of a surfactant 21 or a diluting liquid 21 ′ containing a surfactant and a sample 18, respectively, and the sample adjusting disk 6 is further rotated at the position of the stirring mechanism 3. Is agitated and becomes the adjusted sample 23. The sample dispenser 5 is cleaned by the sample dispenser cleaning mechanism 4 after sucking and discharging the sample 18. The sample adjustment tube 20 is also cleaned by the cleaning mechanism 9 as necessary. The reason for cleaning the sample adjusting tube 20 as needed without cleaning it is that the amount of the adjusting sample 23 in the sample adjusting tube 20 is adjusted for a plurality of analyzes, and the number of necessary items is as follows. Cleaning is performed when the analysis, the required number of times analysis, or the re-examination of the unexpected situation is completed.

  Subsequently, the liquid analysis system performs analysis while transporting the adjusted sample 23 in the sample transport measurement unit 17. First, the sample adjustment disk 6 further rotates, and the sample adjustment tube 20 moves from the position of the agitation mechanism 3 to the position where the adjustment sample input dispenser 11 can be sucked and stops. Here, the adjusted sample charging dispenser 11 sucks a fixed amount of the adjusted sample 23 necessary for the analysis, and then pivots to discharge the adjusted sample 23 from the sample introduction port 38 into the sample transport device 13. A state when the adjusted sample charging dispenser 11 discharges the adjusted sample 23 into the sample transport device 13 will be described with reference to FIG. FIG. 7 shows a state in which the nozzle 41 at the tip of the adjustment sample charging dispenser 11 has entered and discharged the adjustment sample 23 in FIG. The nozzle 41 is made of a conductive material. When the adjustment sample 23 is discharged, the voltage of the power source 51 is applied to the nozzle 41, the second electrode 36 and the adjustment sample 23 in the region where the adjustment sample 23 is discharged as shown in FIG. The switch 43 and the switch 44 are turned on so as to be applied between the first electrodes 34. By turning off only the switch 43 after the discharge of the adjustment sample 23, the adjustment sample 23 does not adhere to the tip of the nozzle 41 even when the nozzle 41 is retracted upward. , That is, between the first substrate 30 and the second substrate 31, and the introduction into the sample transport measurement unit 17 is completed. At substantially the same time as the operation of introducing the adjusted sample 23 into the sample transport measuring unit 17, a certain amount of the reagent 22, 22 'inside the reagent introduction unit 14, 14' from the reagent introduction port 39, 39 'is as shown in FIG. In addition, the sample is introduced into the sample transport measurement unit 17 in the same manner as the introduction of the adjustment sample 23 described above.

8 (1) to 8 (5) are partial cross-sectional views of the sample transport measurement unit 17, and (1) to (5) show the movement of the adjustment sample 23 in time series.
The adjustment sample 23 introduced into the sample transport measurement unit 17 is switched to an AC rectangular shape by sequentially switching the switches 44 wired to the first electrodes 34 as shown in FIGS. 8 (1) to 8 (5). The voltage from the wave power source 51 is sequentially applied to the first electrode 34 and moved by electrostatic force, mixed with the reagents 22 and 22 ′, and further moved to the position of the measuring unit 15. Note that an AC rectangular wave is used as the voltage applied to the first electrode 34 because charging is performed by the insulating film or the water repellent agent on the surface of the first electrode 34 or the second electrode 36 by continuously applying the DC voltage. This is because it was confirmed by experiments that AC voltage is applied to prevent the occurrence of transport due to electrostatic force by applying AC voltage, and that AC square wave can provide greater driving force than AC sine wave. is there. The frequency of the applied AC rectangular wave is preferably 10 Hz or more and 10 kHz or less. When the frequency is less than 10 Hz, the droplet of the adjusted sample moves following the applied frequency and causes vibration. If the frequency is higher than 10 kHz, the driving force for moving to the adjacent electrode is reduced.

  FIG. 9 is a partial cross-sectional view of the measurement unit 15, 15 ′ region of the sample transport measurement unit 17. The adjustment sample 23 moved to the measurement unit 15 is analyzed for the amount of components in the state shown in FIG. That is, the measurement unit 15 is provided with a light source 53 that outputs light 52 of one or two specific wavelengths and a light receiving unit 54 that receives the light 52 that has passed through the adjustment sample 23 and converts it into an electrical signal. Yes. Although the details are omitted, the adjustment sample 23 mixed with the reagents 22 and 22 ′ reacts according to a specific component contained therein and absorbs light of a specific wavelength. From this, the amount of a specific component contained in the adjustment sample 23 can be determined. Since the wavelengths of the reagents 22, 22 ′ and the light 52 are different depending on the type of component to be indexed, they are assigned to each of the plurality of transport paths described in the description of the first electrode 34 at the beginning of the sentence and introduced from the sample introduction port 38. The adjusted sample 23 can be sent to a conveying path for a desired component analysis. In the measuring unit 15 and the measuring unit 15 ′, a combination of a plurality of light sources 53 and a light receiving unit 54 is arranged as shown in FIG. 9, and after the reaction between the adjustment sample 23 and the reagent 22 or the reagent 22 ′, Multiple measurements or measurements at different wavelengths are possible.

  In addition, it has been described that the light 52 having one or two wavelengths is transmitted through the adjustment sample 23 and converted into an electric signal by the light receiving unit 54. However, the white light is transmitted through the adjustment sample 23 and is transmitted by a diffraction grating or a filter after transmission. It is also possible to use a method in which light is split and light of one specific type or two types of wavelengths is converted into an electrical signal.

  In the present invention, the operation up to this point after the adjustment sample 23 is introduced into the sample transport measurement unit 17, that is, the operation until the adjustment sample 23 and the reagent 22 are mixed and reacted and the measurement unit 15 analyzes the component amount. Is configured to be performed twice on one conveyance path. That is, after the component amount is analyzed by the measurement unit 15, the adjusted sample 23 is further moved by electrostatic force, and the reagent 22 'is mixed and reacted, and then measured by the measurement unit 15'. This is because the reaction and measurement are performed twice in order to eliminate the influence of impurities.

  The adjusted sample 23 that has been measured by the measuring unit 15 ′ becomes waste liquid 55, is further moved by electrostatic force, and is collected by the waste liquid collecting unit 16. FIG. 10 shows an enlarged cross section of the waste liquid recovery unit 16 of the sample transport measurement unit 17. The waste liquid collection unit 16 has a sipper 56, and a nozzle 57 at the tip of the waste liquid collection unit 16 is inserted into the sample conveyance measurement unit 17 from the waste liquid collection port 40 of the sample conveyance measurement unit 17. The side of the sipper 56 opposite to the nozzle 57 is connected to a suction pump or the like (not shown) via a valve 58.

  The waste liquid recovery unit 16 of the sample transport measurement unit 17 is located at the end of the transport path by electrostatic force, and the gap between the first substrate 30 and the second substrate 31 is widened from here. When the waste liquid 55 is sent to the widened area 59, the waste liquid 55 that has been crushed by the first substrate 30 and the second substrate 31 until then is released, and it becomes spherical due to the surface tension of the waste liquid 55 itself. Deform. As a result, the waste liquid does not enter the gap between the first substrate 30 and the second substrate 31, the waste liquid 55 heavier than the specific gravity of the oil 33 settles down, and the waste liquid 55 lighter than the specific gravity of the oil 33 floats upward. Accumulated. These accumulated waste liquids are sucked with the sipper 56 by opening the valve 58 and collected.

  The above is the description of the configuration of the liquid analysis system and the analysis method using the liquid analysis system in the present embodiment. Next, addition of a surfactant, which is a major feature of the present invention, will be described.

  In the configuration of the liquid analysis system and the analysis method using the liquid analysis system according to the present invention described above, the surfactant 21 or the diluent 21 ′ containing the surfactant is added to the sample 18, and the sample transport measurement unit 17 is added. Has been introduced. By doing so, it is possible to prevent the reagent from adsorbing to the surfaces of the first substrate 30 and the second substrate 31 and to stably carry by the electrostatic force. The reason will be described below.

  FIG. 11 is a partial cross-sectional view of the sample transport measuring unit 17, FIG. 11 (a) is a schematic view when a sample 18 to which a surfactant is not added is introduced, and FIG. The schematic diagram at the time of introduce | transducing the added adjustment sample 23 is represented.

  In FIG. 11A, since the sample 18 is usually human serum or plasma, it contains about 80 mg of protein 60 such as albumin per ml on average. When such a sample 18 is to be transported by an electrostatic force or the like, the protein 60 is adsorbed on the surface of the first substrate 30 or the second substrate 31, so that the resistance to the transport force is large and the transport becomes impossible. If a flow is generated in the oil 33 or the like, which is a transfer medium, and forced transfer is performed, a part of the protein 60 remains on the surface of the first substrate 30 or the second substrate 31 as a deposit.

  On the other hand, in FIG. 11B, an adjusted sample 23 in which a surfactant is added to the sample 18 is used. The surfactant 61 in the adjustment sample 23 is composed of a hydrophilic group 62 and a hydrophobic group 63 as shown in the schematic diagram of FIG. 12, and inside the adjustment sample 23, as shown in FIG. The hydrophobic group 63 is bound to the protein 60 and encapsulated, and the protein 60 is not adsorbed on the surface of the first substrate 30 or the second substrate 31. Therefore, even when transported by an electrostatic force or the like, since the resistance is small, it can be transported stably, and part of the protein 60 does not remain attached to the surface of the first substrate 30 or the second substrate 31. .

  The amount of the surfactant added to the sample 18 may be added so that the surfactant concentration in the sample is about the saturated micellar concentration, in order to prevent adsorption during transport of the reagent by electrostatic force. Normally, the saturation micelle concentration is about 0.1% by weight of the surfactant and cannot be determined strictly. In the usage amount specified for commercially available laundry detergents, the amount is specified to be 2 to 3 times the saturation micelle concentration. Therefore, it can be said that the upper limit of the amount of the surfactant added to the sample 18 is 0.3% by weight.

  As described in the prior art of this specification, in the movement of a small amount of liquid using electrostatic force, a liquid containing a large amount of surfactant is difficult to move if the interfacial tension is too small. In addition, the analysis accuracy may be affected if a large amount of surfactant is contained. For this reason, the amount of surfactant added is never small, it can be stably transported while preventing adsorption during transport of the reagent due to electrostatic force, and the lower limit of the surfactant that has the least influence on analysis accuracy. Concentration becomes important. FIG. 13 shows the conditions under the condition that the first electrode size is 2 mm × 2 mm, the thickness of the insulating film is 1 μm or less, the distance between the first substrate 30 and the second substrate 31 is 1 mm, and the amount of liquid corresponding to the adjustment sample 23 is 10 μl. In this case, the driving force and resistance force when moving a small amount of liquid using electrostatic force are obtained. The unit of the surfactant concentration in the figure is% by weight. The driving force is a theoretical value obtained by equation (1) in FIG. 14, and the resistance force is a value obtained by experiment by varying the surfactant concentration of the liquid to be driven and the DC voltage applied to the electrode. If it is larger than the force, it can be conveyed. Note that the driving force that increases as the voltage is increased is not shown in this figure, but under the generally used conditions, the force with which the liquid is attracted to the electrode is greater when the DC voltage is about 20 V or more. It is known that it becomes impossible to carry. Considering the above, from the results shown in FIG. 13, it can be said that the lower limit concentration of the surfactant suitable for the above-mentioned conditions is 0.01% by weight.

Next, the type of surfactant used will be described.
Surfactants are roughly classified into nonionic surfactants and ionic surfactants. Surfactants are classified into high molecular weight and low molecular weight. In a liquid analysis system that transports micro liquids using electrostatic force, as described above, a surfactant that can be stably transported while preventing adsorption during transport of reagents, and has minimal impact on analysis accuracy. Is required. Specifically, there is little decrease in the interfacial tension, and the protein is easily micellized, and the protein is not denatured. Taking these into consideration, a nonionic polymer surfactant can be selected as a surfactant suitable for a liquid analysis system by transporting a minute liquid using electrostatic force. The reason for this is that nonionic surfactants generally have a mild effect on proteins. Conversely, ionicity has a strong protein-denaturing effect, and high-molecular surfactants have a lower molecular weight than low molecular weight ones. This is because it has excellent emulsification and dispersibility without reducing the surface tension so much that it is easy to micelleize proteins. Nonionic polymeric surfactants include Polyoxyethylene (10) Octylphenyl Ether, Polyoxyethylene (20) Sorbitan Monolaurate, Polyoxyethylene (20) Sorbitan Monopalmitate, Polyoxyethylene (20) Sorbitan Monostearate, Polyoxyethylene (20) Sorbitan Monooleate Things.

  With the above configuration, serum and plasma samples that contain a large amount of protein such as albumin, which has been difficult to transport in the past, can be transported stably by electrostatic force, etc., enabling stable analysis with very small samples. A liquid analysis system can be provided.

  With reference to FIGS. 15 to 19, an example in which ultrasonic conveyance is used for the sample conveyance measurement unit in the liquid analysis system according to the present invention will be described. The liquid analysis system of this example is the same as that of Example 1 except that the transport method of the sample transport measurement unit 17 is changed from the electrostatic force transport method to the ultrasonic transport method. Only the transfer method will be explained.

First, the principle of the ultrasonic conveyance method will be described. FIG. 15 is a plan view showing the principle diagram of the ultrasonic conveyance system. In the ultrasonic conveyance method, the droplet 71 is moved and conveyed on the surface of the piezoelectric substrate 70. The piezoelectric substrate 70 is made of lead zirconate titanate (PZT), lithium niobate (LiNb0 ₃ ) or the like capable of propagating surface acoustic waves, and has a comb pattern 72 and a comb pattern 72 ′ on the surface as a pair. 73 is arranged as necessary. Each electrode 73 is connected to an AC power source 75 via a switch 74. In this state, when the droplet 71 is placed on the piezoelectric substrate 70 and the switch 74 at a specific location is connected, the surface acoustic wave that travels in the direction of the arrow from the connected electrode 73 to the surface of the piezoelectric substrate 70. Is generated, and the droplet 71 can be moved and conveyed in a direction away from the electrode 73. In FIG. 15, since four electrodes 73 are arranged on a rectangular piezoelectric substrate 70, it is possible to carry within a moving region 76 indicated by hatching. In the present embodiment, in order to prevent the droplets being conveyed from coming off the moving region 76, the surface treatment is performed so that the portion other than the moving region 76 on the surface of the piezoelectric substrate 70 has higher water repellency than the moving region 76. I am doing.

  The configuration of the sample transport measurement unit 17 ′ using the above principle will be described with reference to FIGS. 16, 17, 18, and 19. FIG. 16 is a diagram in which only the sample transport measurement unit is extracted, and a plan view is partially shown in section. FIG. 17 is a sectional view of FIG. 16 viewed from the front. 18 and 19 show a partially enlarged view of FIG.

  As shown in FIGS. 16 and 17, the sample transport measurement unit 17 ′ includes a first substrate 80 made of lithium niobate, which is a transparent piezoelectric material, and a transparent glass or ceramic disposed in parallel with the first substrate 80. Or a second substrate 81 made of resin, and a spacer 82 that keeps the first substrate 80 and the second substrate 81 parallel and at a constant distance. On the side of the first substrate 80 facing the second substrate 81, a plurality of electrodes 73 described in the principle diagram are arranged as shown in the figure, and at least either the first substrate 80 or the second substrate 81 has a moving region. The area 76 is indicated by hatching, and the water repellency is higher than the movement area 76 in the portions other than the movement area 76 on the facing surfaces of the first substrate 80 and the second substrate 81. . Each electrode 73 is connected to an AC power source 75 via a switch 74.

  In the second substrate 81, the sample introduction port 88 for introducing the adjustment sample into the sample transport measurement unit 17 ′, and the reagent introduction ports 89 and 89 ′ for introducing the reagents 22 and 22 ′ are formed into a long cylindrical shape, and the analysis is completed. The waste liquid collection port 40 for taking out the waste liquid as a waste liquid is provided in a state of rising in a cylindrical shape. The spacer 82 is for maintaining the first substrate 80 and the second substrate 81 in parallel and at a constant distance as described above, and seals between the first substrate 80 and the second substrate 81 to reduce the internal humidity. It is possible to keep.

  18 and 19 are cross sections of the sample introduction port 88 and the reagent introduction ports 89 and 89 ', both of which are shown in a cross section in the longitudinal direction of the rise of the long cylindrical shape. When the adjustment sample 23 or the reagents 22 and 22 ′ are introduced into the sample transport measurement unit 17 ′ from the sample introduction port 88 and the reagent introduction ports 89 and 89 ′, the reagent introduction unit 14 whose tip is bent in an L shape in the horizontal direction. , 14 ′, or the nozzle 41 whose tip is bent in the L-shape in the horizontal direction is moved in the order shown in FIGS. 18 and 19, and the L-shaped horizontal portion is located between the first substrate 30 and the second substrate 31. It enters and discharges the adjustment sample 23 or the reagents 22 and 22 '.

  The adjustment sample 23 and the reagents 22 and 22 ′ introduced into the sample transport measurement unit 17 ′ are the same as in the first embodiment while moving and stopping by selectively connecting and disconnecting the switch 74 shown in FIG. Then, it is measured by the measuring unit 15 and the measuring unit 15 ′ and collected by the waste liquid collecting port 40.

  As described at the beginning of the second embodiment, since the adjustment sample 23 and the reagents 22, 22 'are the same as those in the first embodiment except for the transfer method, the description other than the transfer method is omitted. In particular, regarding the addition of the surfactant, which is a major feature of the present invention, a great effect is exhibited also in this example.

  An example in which the transport medium flow is used for the sample transport measurement unit in the liquid analysis system according to the present invention will be described with reference to FIGS. The liquid analysis system according to the present embodiment is the same as that of the first embodiment except that the transport method of the sample transport measurement unit 17 is changed from the electrostatic force transport method to the transport medium flow transport method as in the second embodiment. Therefore, only the transfer method will be described assuming that the sample transfer measurement unit is 17 ″.

  First, the principle of the transport medium flow transport system will be described. 20 is a view showing a sample conveyance measuring unit 17 ″ by the conveyance medium flow conveyance method, and is a partially sectional plan view. FIG. 21 is a sectional view of the AA portion of FIG.

  The sample transport measuring unit 17 ″ includes a first substrate 90 made of transparent glass, ceramic, or resin, a second substrate 91 made of the same material arranged in parallel with the first substrate 90, the first substrate 90 and the second substrate 90. The substrate 91 is composed of an outer spacer 92 and inner spacers 93 and 93 ′ that keep the substrate 91 parallel and at a constant distance. After being joined so that the liquid to be transported and the transport medium do not leak from the internal space, the first substrate 90 or the second substrate 91 is filled with silicone or fluorine-based oil 94 as a transport medium, filled with an internal space consisting of the first substrate 90, the second substrate 91, and the outer spacer 92. The oil 94 circulates inside the flow path formed by the inner spacers 93 and 93 ′ by the medium flow generation unit 95. The medium flow generation unit 95 is attached to a transport medium for transporting a sample or the like. , Which generates a liquid flow, is a part that has a pump or water wheel-like member inside that generates a flow that circulates to the medium by discharging the medium taken in from one end to the other end, and generates a flow Regardless of the principle, the flow rate may be controlled according to the flow load, and the first substrate 90 has a transported liquid capturing means 96 for capturing a transported liquid such as a sample.

  In the second substrate 91, the sample introduction port 97 for introducing the adjustment sample into the sample transport measurement unit 17 ″ and the reagent introduction ports 98 and 98 ′ for introducing the reagents 22 and 22 ′ are formed into a long cylindrical shape, and the sample which has been analyzed. A waste liquid recovery port 99 is provided in a state where the liquid recovery port 99 rises in a cylindrical shape, and the adjustment sample 23 introduced from the sample introduction port 97 and the reagents 22 and 22 ′ introduced from the reagent introduction ports 98 and 98 ′. Is transported by the flow of the oil 94 generated by the medium flow generation unit 95, and is captured and stopped by the transported liquid capturing means 96. At this time, the flow of the oil 94 generated by the medium flow generation unit 95 is stagnant. Instead, the width X of the transport liquid capturing means 96 and the diameter D of the adjusted sample, reagent, or mixed liquid thereof are set smaller than the flow path width W so as to flow as shown in FIG.

  The capturing principle of the transported liquid capturing means 96 according to this embodiment will be described with reference to FIG. FIG. 23 is a partially enlarged view of FIG. On the side of the first substrate 90 facing the second substrate 91, the first electrode 100 made of a conductive thin film is disposed at the transported liquid capturing position, the surface of the electrode 100 is covered with the insulating film 101, and the second electrode The surface facing the substrate 91 is water repellent. Since the first electrode 100 and the insulating film 101 are very thin and cannot be written even if enlarged, the thickness direction is exaggerated as shown in FIG. On the second substrate 91, the second electrode 102 is disposed on the entire surface facing the first substrate 90 or in a range covering at least the portion facing the first electrode 100, similar to the first electrode 100. In addition, the surface on the side facing the first substrate 90 is subjected to water repellent treatment. Note that the insulating film 103 is not necessarily required, and the surface on the side facing the first substrate 90 may be water-repellent. The first electrode 100 and the second electrode 102 are connected to an AC rectangular wave power source 105 via a switch 104. Further, all the first electrodes 100 may be wired so as to have the same potential, and in that case, only one switch 104 may be provided.

  In this state, the adjustment sample 23 and the reagents 22 and 22 ′ conveyed by the flow of the oil 94 have the switch 104 connected as shown in FIG. When the switch 104 is released as shown in FIG. 23B, it is transported by the flow of the oil 94 and recovered at the waste liquid recovery port 99.

  As described in the beginning of the third embodiment, the method other than the transport method for the adjustment sample 23 and the reagents 22 and 22 ′ is the same as that of the first embodiment, and the description other than the transport method is omitted. In particular, regarding the addition of the surfactant, which is a major feature of the present invention, a great effect is exhibited also in this example. In addition, since the voltage from the AC rectangular wave power source 105 applied to the first electrode 100 and the second electrode 102 is an AC rectangular wave, the insulating film on the electrode surface and the water repellent agent are prevented from being charged, It makes it possible to operate stably over time.

It is a top view which shows the structural example of the liquid analysis system by this invention. It is sectional drawing from the front side which shows the structural example of the liquid analysis system by this invention. It is sectional drawing of a sample cassette part. It is the top view which carried out the partial cross section of the sample conveyance measurement part. It is sectional drawing which looked at FIG. 4 from the front. It is a fragmentary sectional view of FIG. It is a fragmentary sectional view of FIG. It is a fragmentary sectional view of a sample conveyance measurement part showing a situation of movement of an adjustment sample in time series. It is a fragmentary sectional view of a sample conveyance measurement part showing a measurement part field. It is a fragmentary sectional view of a sample conveyance measurement part showing a waste liquid recovery part. It is a fragmentary sectional view of a sample conveyance measurement part. It is a schematic diagram of surfactant. It is the graph which calculated | required the driving force and the resistance force at the time of the movement of the trace amount liquid using an electrostatic force. It is a formula for obtaining a driving force when moving a trace amount liquid using an electrostatic force. It is a top view which shows the principle figure of an ultrasonic conveyance system. It is explanatory drawing of the sample conveyance measurement part of an ultrasonic conveyance system. It is sectional drawing which looked at FIG. 16 from the front. It is sectional drawing of a sample inlet and a reagent inlet. It is sectional drawing of a sample inlet and a reagent inlet. It is explanatory drawing of the sample conveyance measurement part by a conveyance medium flow conveyance system. It is sectional drawing of the AA part of FIG. It is a top view showing the diameter of a conveyance liquid capture | acquisition means with respect to a flow path width, and a liquid. It is the elements on larger scale of FIG.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Sample cassette insertion conveyance part, 2 ... Sample cassette, 3 ... Agitation mechanism, 4 ... Sample dispenser washing mechanism, 5 ... Sample dispenser, 6 ... Sample adjustment disk, 7 ... Surfactant tank, 8 ... Surfactant Dispenser, 9 ... cleaning mechanism, 10 ... sample adjusting unit, 11 ... adjusted sample loading dispenser, 12 ... adjusted sample loading dispenser cleaning mechanism, 13 ... sample transport device, 14 ... reagent loading unit, 14 '... reagent loading unit, 15 ... Measurement unit, 15 '... Measurement unit, 16 ... Waste liquid collection unit, 17 ... Sample transport measurement unit, 18 ... Sample, 19 ... Sample tube, 20 ... Sample adjustment tube, 21 ... Surfactant, 21' ... Surfactant 22 ... Reagent, 22 '... Reagent, 23 ... Preparation sample, 30 ... First substrate, 31 ... Second substrate, 32 ... Spacer, 33 ... Oil, 34 ... First electrode, 35 ... Insulating film 36 ... second electrode 37 ... insulating film 38 ... sample introduction port 39 ... reagent introduction port 39 '... reagent introduction port 40 ... waste liquid recovery port 41 ... nozzle 42 ... power source 43 ... switch 44 ... Switch, 50 ... Switch, 51 ... AC rectangular wave power supply, 52 ... Light, 53 ... Light source, 54 ... Light receiving part, 55 ... Waste liquid, 56 ... Sipper, 57 ... Nozzle, 58 ... Valve, 60 ... Protein, 61 ... Interface Activator, 62 ... hydrophilic group, 63 ... hydrophobic group, 70 ... piezoelectric substrate, 71 ... droplet, 72 ... comb pattern, 72 '... comb pattern, 73 ... electrode, 74 ... switch, 75 ... AC power supply, 76 ... moving region, 80 ... first substrate, 81 ... second substrate, 82 ... spacer, 88 ... sample inlet, 89 '... reagent inlet, 89 ... reagent inlet, 90 ... first substrate, 91 ... second Substrate, 92 ... outer spacer, 93 ... inner spacer, 3 ... inner spacer, 94 ... oil, 95 ... medium flow generating section, 96 ... transported liquid capturing means, 97 ... sample inlet, 98 ... reagent inlet, 98 '... reagent inlet, 99 ... waste liquid recovery port, DESCRIPTION OF SYMBOLS 100 ... 1st electrode, 101 ... Insulating film, 102 ... 2nd electrode, 103 ... Insulating film, 104 ... Switch, 105 ... AC rectangular wave power supply.

Claims (10)

A sample preparation unit for adding a surfactant to the sample;
A first substrate and a second substrate substantially parallel to the first substrate;
A sample introduction part for introducing a sample to which the surfactant is added between the first substrate and the second substrate;
Transport for transporting said first substrate a sample the surfactant introduced is added between the second substrate, along a transport path which is set between the first substrate and the second substrate Part,
A reagent introduction part for introducing a reagent onto the transport path set between the first substrate and the second substrate;
A carrier medium introducing section for introducing a carrier medium between the first substrate and the second substrate;
Possess an analysis unit for analyzing a component amount contained in the sample,
The transport unit performs transport by applying a voltage to the sample to which the surfactant is added,
The sample analysis system , wherein the sample preparation unit adds the surfactant so that a weight concentration after addition to the sample is 0.01% or more .   2. The sample analysis system according to claim 1, wherein the sample preparation unit adds the surfactant to the sample so that the concentration of the surfactant after the addition is about a critical micelle concentration. Sample analysis system. 2. The sample analysis system according to claim 1, wherein the sample preparation unit has a concentration with respect to weight of 0 . A sample analysis system, wherein the surfactant is added so as to be 3% or less.   2. The sample analysis system according to claim 1, wherein the surfactant is a nonionic surfactant.   2. The sample analysis system according to claim 1, wherein the surfactant is a nonionic polymer surfactant.   2. The sample analysis system according to claim 1, wherein the surfactant is Polyoxyethylene (10) Octylphenyl Ether, Polyoxyethylene (20) Sorbitan Monolaurate, Polyoxyethylene (20) Sorbitan Monopalmitate, Polyoxyethylene (20) Sorbitan Monostearate, Polyoxyethylene (20) Sorbitan Monooleate. A sample analysis system comprising any of the above.   2. The sample analysis system according to claim 1, wherein the carrier medium is silicone oil or fluorine oil. The specimen processing system according to claim 1, wherein the transport section, the sample analysis system, wherein the benzalkonium to apply an AC rectangular wave. The specimen processing system according to claim 1, wherein the transport section, the sample analysis system frequency is characterized and Turkey to apply an AC rectangular wave of 10Hz or 10kHz or less. Adding a surfactant to the sample to make an adjusted sample;
Introducing a carrier medium between a first substrate and a second substrate substantially parallel to the first substrate;
Introducing the adjustment sample between the first substrate and the second substrate;
Introduced the adjustment sample possess a step of conveying between the first substrate and the second substrate,
In the step of preparing the preparation sample, the surfactant is added so that the weight concentration after addition to the sample is 0.01% or more,
The sample transport method , wherein the transport is performed by applying a voltage to the adjusted sample .

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