JP2006284350A - Dispenser, attaching method of pipette chip of dispenser and measuring instrument utilizing attenuation of total reflection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To suppress the irregularity in the insertion quantity to a nozzle of a pipette head. <P>SOLUTION: The nozzle 54a for sucking and discharging a liquid is formed to the pipette head 54. The nozzle 54a is protruded in an almost cylindrical shape from the end surface of the pipette head 54 and its outer diameter almost coincides with the inner diameter of a pipette tip 62. The pipette tip 62 is held to the pipette head 54 by the fitting with the nozzle 54a. An adjusting jig 64 is provided with an adjusting hole 70 formed so as to be slightly larger than the outer shape of the pipette tip 62. The pipette tip 62 is inserted in the nozzle 54a before inserted in the adjusting hole 70. The leading end 62a of the pipette tip 62 is pressed to the base 70a of the adjusting hole 70 to adjust the insertion quantity of the pipette tip 62. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a dispensing device for dispensing a liquid by inserting a substantially cylindrical pipette tip into a nozzle for sucking and discharging a liquid, a method for attaching the pipette tip, and a surface provided with the dispensing device. The present invention relates to a measuring apparatus using total reflection attenuation such as plasmon resonance.

  2. Description of the Related Art There are known measuring apparatuses that measure the reaction of a sample by using total reflection attenuation when measuring an interaction between biochemical substances such as proteins and DNA, screening drugs, and the like.

  One of the measuring devices that use such total reflection attenuation is a measuring device that uses a surface plasmon resonance phenomenon (hereinafter referred to as an SPR measuring device). The surface plasmon is generated by the collective vibration of free electrons in the metal, and is a density wave of free electrons traveling along the surface of the metal.

  For example, in an SPR measurement apparatus that employs a Kretschmann arrangement known from Patent Document 1 or the like, a surface of a metal film formed on a transparent dielectric (hereinafter referred to as a prism) is used as a sensor surface, and a sample is formed on the sensor surface. After reacting, the metal film is irradiated from the back side of the sensor surface through the prism so as to satisfy the total reflection condition, and the reflected light is measured.

  Of the light irradiated to the metal film so as to satisfy the total reflection condition, a small amount of light called an evanescent wave passes through the metal film without being reflected and oozes out to the sensor surface side. At this time, if the frequency of the evanescent wave coincides with the frequency of the surface plasmon, SPR is generated and the intensity of the reflected light is greatly attenuated. In addition, the incident angle (resonance angle) of light at which this attenuation occurs varies depending on the refractive index on the metal film. That is, the SPR measurement device measures the reaction state of the sample on the sensor surface by capturing the reflected light from the metal film and detecting the resonance angle.

  By the way, biological samples such as proteins and DNA are often handled as sample solutions dissolved in a solvent such as physiological saline, pure water, or various buffer solutions in order to prevent denaturation and inactivation due to drying. The SPR measurement device described in Patent Document 1 is for examining such interaction between biological samples, and a flow path for feeding a sample solution is provided on the sensor surface. The flow path and the prism are arranged on a measurement stage provided in the apparatus main body, and the above-described measurement can be performed by mounting a chip-type sensor unit having a metal film formed on a glass substrate on the measurement stage. Done.

  In Patent Document 1, the sample solution is directly fed into the flow path from a container for storing the sample solution via a pipe (tube) connected to a pump, a valve, or the like. There is a problem that so-called contamination is likely to occur, in which the sample is mixed into a sample solution to be injected later.

In order to solve this problem, the present applicant uses a pipette consisting of a substantially conical cylindrical pipette tip with a small hole formed at the tip and a head portion that detachably holds the pipette tip, and attaches it to the container An SPR measurement device that dispenses a stored liquid such as a sample solution into a flow path has been proposed (see, for example, Japanese Patent Application No. 2004-287615). In this SPR measurement device, contamination occurring when liquid is fed into the flow path can be prevented by exchanging the pipette tip for each liquid to be dispensed.
Japanese Patent No. 3294605

  The pipette tip is attached by moving the head portion to a case in which a plurality of pipette tips are stored, and inserting a nozzle formed in the head portion into the pipette tip and mechanically fitting them. At this time, the case may be distorted by the pressing force at the time of insertion, and the amount of insertion between the nozzle and the pipette tip may vary. For example, if the insertion is shallow, after the pipette tip is inserted into the flow path and the liquid is dispensed, the pipette tip comes out of the nozzle when it is pulled out of the flow path, and the pipette tip remains stuck in the flow path. End up. Further, when the pipette tip is inserted obliquely with respect to the nozzle, the pipette tip does not pierce the flow path, or the sensor unit is moved to disturb the SPR signal.

  The present invention has been made in view of the above problems, and an object thereof is to suppress variations in the amount of insertion of the pipette tip into the nozzle.

  In order to achieve the above object, a dispensing device according to the present invention includes a dispensing head in which a nozzle for sucking and discharging a liquid is formed, and a substantially cylindrical pipette tip inserted into the nozzle is detachably held. An adjustment jig in which an adjustment hole into which at least a part of the pipette is inserted, an abutment surface substantially orthogonal to the insertion direction of the pipette tip, and the pipette tip held by the dispensing head are formed. And a pressing means for pressing a part of the pipette tip against the contact surface.

  It is preferable to provide a pipette detection means for detecting whether or not the pipette tip is inserted into the adjustment hole.

  It is preferable that a plurality of nozzles are formed in the dispensing head, and a plurality of adjustment holes corresponding to the number of the plurality of pipette tips inserted into the plurality of nozzles are provided in the adjustment jig.

  Furthermore, it is preferable that the pressing means includes a head moving mechanism that moves the dispensing head in three directions, front, rear, left, right, and up, and a control unit that controls the amount of movement of the head moving mechanism in each direction.

  Moreover, it is preferable that the contact surface is a bottom surface of the adjustment hole, and the pressing means presses the tip of the pipette tip against the bottom surface.

  The pipette tip mounting method of the present invention has a dispensing head provided with a dispensing head in which a nozzle for sucking and discharging a liquid is formed and a substantially cylindrical pipette tip inserted into the nozzle is detachably held. In the apparatus, after the pipette tip is inserted into the nozzle, the pipette tip is pressed against a contact surface substantially orthogonal to the insertion direction of the pipette tip, and the pipette tip is inserted into the nozzle. It is characterized by adjusting the amount.

  Further, when the pipette tip is pressed against the contact surface, it is preferable that a uniform force is applied to the pipette tip with respect to the insertion direction.

  Further, the measuring device using total reflection attenuation according to the present invention includes a dielectric block having a thin film layer formed on one surface, and a flow path member having a flow path for supplying a sample solution to the thin film layer. A light source that irradiates the sensor unit with light so as to satisfy the total reflection condition, a light detection means that receives reflected light from the sensor unit and photoelectrically converts it into an electrical signal, and suction and discharge of the sample solution And a dispensing means for removably holding a substantially cylindrical pipette tip inserted into the nozzle, and a dispensing means for injecting the sample solution into the flow path; and An adjustment jig in which an adjustment hole into which at least a part is inserted, an abutment surface substantially orthogonal to the insertion direction of the pipette tip, and the pipette tip held by the dispensing head are adjusted. Inserted into, characterized by providing a pressing means for pressing a portion of the pipette tip the contact surface.

  According to the dispensing device of the present invention and the measuring device using total reflection attenuation, the pipette tip held by the dispensing head is inserted into the adjustment hole, and the abutment surface substantially orthogonal to the insertion direction of the pipette tip Since a part of the pipette tip is pressed against the pipette, the amount of insertion of the pipette tip into the nozzle is adjusted by the pressing, and variation in the amount of insertion can be suppressed. Further, by inserting the pipette tip into the adjustment hole, the orientation of the pipette tip can be straightened along the inner wall surface of the adjustment hole when the pipette tip is inserted obliquely with respect to the nozzle.

  As shown in FIG. 1, the measurement method using SPR is roughly divided into three steps: a fixing step, a measurement processing step (data reading step), and a data analysis step. The SPR measuring device includes a fixing machine 10 that performs a fixing process, a measuring machine 11 that performs a measuring process, and a data analyzer that analyzes data obtained by the measuring machine 11.

  The measurement is performed using the sensor unit 12 that is an SPR sensor. The sensor unit 12 has a metal film (thin film layer) 13 whose one surface becomes a sensor surface 13a on which SPR occurs, and a prism (dielectric block) 14 bonded to the light incident surface 13b on the back surface of the sensor surface 13a. And a flow path member 41 which is disposed to face the sensor surface 13a and in which a flow path 16 through which a ligand or an analyte is fed is formed.

  As the metal film 13, for example, gold or silver is used, and the film thickness is, for example, 50 nm. This film thickness is appropriately selected according to the material of the metal film, the emission wavelength of the irradiated light, and the like. The prism 14 is a transparent dielectric having the metal film 13 formed on the upper surface thereof, and condenses the light irradiated so as to satisfy the total reflection condition toward the light incident surface 13b. The channel 16 is a liquid feeding pipe bent in a substantially U shape, and has an inlet 16a for injecting liquid and an outlet 16b for discharging it. The tube diameter of the channel 16 is, for example, about 1 mm, and the interval between the inlet 16a and the outlet 16b is, for example, about 10 mm.

  The bottom of the channel 16 is open, and this open part is covered and sealed with the sensor surface 13a. A sensor cell 17 is constituted by the flow path 16 and the sensor surface 13a. As will be described later, the sensor unit 12 includes a plurality of such sensor cells 17 (see FIG. 3).

  The fixing step is a step of fixing the ligand to the sensor surface 13a. The fixing process is performed by setting the sensor unit 12 to the fixing machine 10. The fixing machine 10 is provided with a pipette pair 19 including a pair of pipettes 19a and 19b. In the pipette pair 19, the pipettes 19a and 19b are inserted into the inlet 16a and the outlet 16b, respectively. Each of the pipettes 19a and 19b has a function of injecting liquid into the flow channel 16 and sucking out from the flow channel 16, and when one of them performs the injection operation, the other performs the suction operation. So that they work together. Using this pipette pair 19, a ligand solution 21 in which a ligand is dissolved in a solvent is injected from the injection port 16a.

  A linker film 22 that binds to the ligand is formed at substantially the center of the sensor surface 13a. The linker film 22 is formed in advance at the manufacturing stage of the sensor unit 12. Since the linker film 22 serves as a fixing group for fixing the ligand, it is appropriately selected according to the type of ligand to be fixed.

  Before performing the ligand immobilization process for injecting the ligand solution 21, first, the immobilization buffer solution is sent to the linker film 22, and the linker film 22 is moistened to facilitate the binding of the ligand film 22. Processing is performed. For example, in the amine coupling method, carboxymethyl dextran is used as the linker film 22, and the amino group in the ligand is directly covalently bonded to the dextran. As the activation liquid in this case, a mixed liquid of N ′-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) is used. After this activation process, the flow path 16 is washed with the fixing buffer solution.

  As the buffer solution for fixing and the solvent (diluent) of the ligand solution 21, for example, various buffer solutions (buffer solutions), physiological salt solutions represented by physiological saline, and pure water are used. The The type of each of these liquids, the pH value, the type of mixture and its concentration, etc. are appropriately determined according to the type of ligand. For example, when a biological substance is used as a ligand, physiological saline whose pH is adjusted to near neutral is often used. However, in the amine coupling method, the linker film 22 is negatively (negatively) charged by carboxymethyl dextran. Therefore, the protein is positively (positively) charged so as to be easily bonded to the linker film 22. In some cases, a phosphate buffer solution (PBS: phosphatic-buffered, saline) having a strong buffering action containing a high concentration of phosphate may be used.

  After such activation processing and cleaning, the ligand solution 21 is injected into the sensor cell 17 and the ligand immobilization processing is performed. When the ligand solution 21 is injected into the flow path 16, the ligand 21 a diffusing in the solution gradually approaches the linker film 22 and binds. In this way, the ligand 21a is fixed to the sensor surface 13a. Immobilization usually takes about one hour, and during this time, the sensor unit 12 is stored in a state where environmental conditions including temperature are set to predetermined conditions. The ligand solution 21 in the channel 16 may be allowed to stand while the immobilization proceeds, but the ligand solution 21 in the channel 16 is preferably stirred and flowed. By doing so, the binding between the ligand and the linker film 22 is promoted, and the amount of the ligand immobilized can be increased.

  When the immobilization of the ligand 21a on the sensor surface 13a is completed, the ligand solution 21 is discharged from the flow path 16. The ligand solution 21 is sucked and discharged by the pipette 19b. After the immobilization, the sensor surface 13a is subjected to a cleaning process by injecting a cleaning liquid into the channel 16. After this washing, if necessary, a blocking liquid is injected into the flow path 16 to perform a blocking process for inactivating the reactive group to which no ligand is bound in the linker film 22. As the blocking liquid, for example, ethanolamine-hydrochloride is used. After this blocking process, the channel 16 is washed again. Thereafter, the drying preventing liquid is injected into the flow path 16. Thus, the sensor unit 12 is stored until measurement in a state in which the sensor surface 13a is immersed in the anti-drying liquid.

  The measurement process is performed with the sensor unit 12 set on the measuring machine 11. The measuring machine 11 is also provided with a pipette pair 26 similar to the pipette pair 19 of the fixing machine 10. By the pipette pair 26, various liquids are injected into the flow path 16 from the injection port 16a. In the measurement process, first, a measurement buffer solution is injected into the flow path 16. Thereafter, an analyte solution 27 in which the analyte is dissolved in a solvent is injected, and then the measurement buffer solution is injected again. Note that the flow path 16 may be once cleaned before the measurement buffer solution is first injected. Data reading is started immediately after the measurement buffer is first injected in order to detect a reference signal level, and is performed after the analyte solution 27 is injected and until the measurement buffer is injected again. . As a result, it is possible to measure the SPR signal until detection of the reference level (baseline), reaction state (binding state) of the analyte and ligand, and desorption of the combined analyte and ligand by injection of the buffer solution for measurement. it can.

  As the buffer solution for measurement and the solvent (diluted solution) of the analyte solution 27, for example, various buffer solutions (buffer solutions), physiological salt solutions represented by physiological saline, and pure water are used. Is done. The type of each of these liquids, the pH value, the type of mixture, its concentration, etc. are appropriately determined according to the type of ligand. For example, DMSO (dimethyl-sulfo-oxide) may be included in physiological saline in order to facilitate the dissolution of the analyte. This DMSO greatly affects the signal level. As described above, the measurement buffer solution is used for detection of the reference level. Therefore, when DMSO is contained in the solvent of the analyte, the measurement buffer solution having a DMSO concentration similar to the DMSO concentration should be used. Is preferred.

  The analyte solution 27 is often stored for a long period of time (for example, one year). In such a case, a concentration difference occurs between the initial DMSO concentration and the DMSO concentration at the time of measurement due to a change over time. May end up. When strict measurement is required, such a concentration difference is estimated from the level of the reference signal (ref signal) when the analyte solution 27 is injected, and correction (DMSO concentration correction) is performed on the measurement data. Is called.

  Here, as will be described later, the reference signal (ref signal) is an SPR signal corresponding to a reference region provided on the sensor surface where the ligand is not fixed, and a measurement region where the ligand is fixed and a reaction with the analyte occurs. It is a signal that is compared and referenced with the measurement signal (act signal). At the time of measurement, two signals of the measurement signal and the reference signal are detected, and at the time of data analysis, for example, a difference between the two SPR signals is taken and analyzed as measurement data. By doing so, for example, noise caused by disturbances such as individual differences between a plurality of sensor cells and liquid temperature changes can be canceled, and a signal with a good S / N ratio can be obtained. .

  The correction data for correcting the DMSO concentration is obtained by injecting a plurality of types of measurement buffer solutions having different DMSO concentrations into the sensor cell 17 before injecting the analyte solution 27, and changing the ref according to the change in DMSO concentration at this time. It is obtained by examining the amount of change in each of the signal level and the act signal level.

  The measurement unit 31 includes an illumination unit 32 and a detector (light detection means) 33. As described above, since the reaction state between the ligand and the analyte appears as a change in the resonance angle (incident angle of the light irradiated to the light incident surface), the illumination unit 32 can perform various incidents that satisfy the total reflection condition. The light of the corner is irradiated to the light incident surface 13b. The illumination unit 32 includes, for example, a light source 34 and an optical system 36 including a condensing lens, a diffuser plate, and a polarizing plate. The arrangement position and the installation angle satisfy the total reflection condition in terms of the incident angle of illumination light. To be adjusted.

  As the light source 34, for example, a light emitting element such as an LED (Light Emitting Diode), an LD (Laser Diode), or an SLD (Super Luminescent Diode) is used. One such light emitting element is used, and light is emitted from the single light source toward one sensor cell 17. When measuring a plurality of sensor cells 17 at the same time, the light from a single light source may be dispersed and irradiated to the plurality of sensor cells 17, or one light emitting element is provided for each sensor cell 17. A plurality of light emitting elements may be used side by side so as to be allocated. The diffusion plate diffuses light from the light source 34 and suppresses unevenness in the amount of light in the light emitting surface. The polarizing plate allows only p-polarized light that causes SPR to pass through. In addition, when using LD, when the direction of polarization of the light itself emitted from the light source is uniform, the polarizing plate is unnecessary. In addition, even when a light source with uniform polarization is used, if the direction of polarization becomes uneven by passing through the diffusion plate, the direction of polarization is aligned using a polarizing plate. The light thus diffused and polarized is condensed by the condenser lens and irradiated onto the prism 14. As a result, it is possible to cause the light incident surface 13b to enter the light rays having various incident angles without variation in light intensity.

  The detector 33 receives the light reflected by the light incident surface 13b and outputs an electrical signal having a level corresponding to the light intensity. Since light rays are incident on the light incident surface 13b at various angles, the light rays are reflected on the light incident surface 13b at various reflection angles according to respective incident angles. The detector 33 receives light beams having these various reflection angles. When a change occurs in the medium on the sensor surface 13a, the refractive index changes, and the incident angle (resonance angle at which SPR occurs) of the light whose reflected light intensity is attenuated also changes. When the analyte is fed onto the sensor surface 13a, the refractive index on the sensor surface 13a changes according to the reaction state between the analyte and the ligand, and the resonance angle also changes accordingly.

  The detector 33 uses, for example, a CCD area sensor or a photodiode array, receives reflected light reflected at various reflection angles on the light incident surface 13b, photoelectrically converts them, and outputs them as SPR signals. The reaction state of the ligand and the analyte appears as a transition of the attenuation position of the reflected light in the light receiving surface. For example, before and after the analyte contacts the ligand, the refractive index on the sensor surface 13a is different, and the resonance angle at which SPR occurs is different. When the analyte comes into contact with the ligand and starts the reaction, the resonance angle starts to change accordingly and the attenuation position of the reflected light in the light receiving surface starts to move. An SPR signal representing the reaction situation thus obtained is output to the data analyzer. In the data analysis step, the SPR signal obtained by the measuring instrument 11 is analyzed to analyze the characteristics of the analyte.

  For the sake of convenience, in FIG. 1, the direction of the incident light beam on the light incident surface 13 b and the reflected light beam reflected there is the flow direction of the liquid in the flow channel 16 so that the configuration of the measurement unit 31 becomes clear. Although the illumination unit 32 and the detector 33 are arranged so as to be parallel to each other, as shown in FIG. 2, the directions of the incident light beam and the reflected light beam are actually orthogonal to the flow direction. The illumination unit 32 and the detector 33 are arranged so as to be irradiated. Of course, the measurement unit 31 may be arranged and measured as shown in FIG.

  As shown in FIG. 2, on the linker film 22, a measurement region (act region) 22 a where a ligand is immobilized and a reaction between the analyte and the ligand occurs, and the ligand is not immobilized. A reference region (ref region) 22b for obtaining a reference signal is formed. The ref region 22b is formed when the linker film 22 described above is formed. As a formation method, for example, the linker film 22 is subjected to a surface treatment, and a binding group that binds to a ligand is deactivated in a region about half of the linker film 22. Thereby, half of the linker film 22 becomes the act region 22a, and the other half becomes the ref region 22b.

  The detector 33 outputs an SPR signal corresponding to the act region 22a as an act signal, and outputs an SPR signal corresponding to the ref region 22b as a ref signal. The act signal and the ref signal are measured almost simultaneously from the detection of the reference level to the desorption through the binding reaction. Data analysis is performed by obtaining the difference or ratio between the act signal and the ref signal thus obtained. For example, the data analyzer obtains difference data between the act signal and the ref signal, uses the difference data as measurement data, and performs analysis based on the difference data. By doing this, as described above, noise caused by disturbances such as individual differences between sensor units and sensor cells, mechanical fluctuations of the device, and temperature changes of the liquid can be canceled. Is possible.

  The illumination unit 32 and the detector 33 are configured so as to be able to measure two channels of these act signals and ref signals. For example, the illuminating unit 32 splits one light emitting element into a plurality of light beams incident on the act region 22a and the ref region 22b using a reflection mirror or the like. Each light beam is received by a detector 33 constituted by a plurality of photodiode arrays for each channel.

  When a CCD area sensor is used as the detector 33, the reflected light of each channel simultaneously received can be recognized as an act signal and a ref signal by image processing. However, when such a method using image processing is difficult, the timings of incidence on the act region 22a and the ref region 22b may be shifted by a minute time to receive the signal of each channel. As a method of shifting the incident timing, for example, a disk with two holes formed at a position shifted by 180 degrees on the optical path is arranged, and this disk is rotated to rotate the incident timing of each channel. Is shifted. Each hole is arranged at a position where the distance from the center is different by the distance between the regions 22a and 22b, so that when one hole enters the optical path, a light beam enters the act region 22a and the other When the hole enters the optical path, the light beam enters the ref region 22b.

  FIG. 3 is an exploded perspective view of the sensor unit 12. The sensor unit 12 is held in a state in which the flow path member 41 in which the flow path 16 is formed, the prism 14 with the metal film 13 formed on the upper surface, and the bottom surface of the flow path member 41 and the upper surface of the prism 14 are joined. And a lid member 43 disposed above the holding member 42.

  In the flow path member 41, for example, three flow paths 16 are formed. The flow path member 41 is formed in an elongated shape, and the three flow paths 16 are arranged along the longitudinal direction thereof. This flow path 16 constitutes a sensor cell 17 (see FIG. 1) together with the metal film 13 bonded to the bottom surface thereof. Therefore, the flow path member 41 is formed of an elastic material such as rubber or PDMS (polydimethylsiloxane) in order to improve the adhesion with the metal film 13. As a result, when the bottom surface of the flow path member 41 is pressed against the top surface of the prism 14, the flow path member 41 is elastically deformed to fill the gap between the joint surfaces with the metal film 13, and the open bottom of each flow path 16 is the prism. The upper surface of 14 is covered with water. In this example, the example in which the number of the flow paths 16 is three has been described. Of course, the number of the flow paths 16 is not limited to three, and may be one or two, or four or more. But you can.

  A metal film 13 is formed on the upper surface of the prism 14 by vapor deposition. The metal film 13 is formed in a strip shape so as to face the plurality of channels 16 formed in the channel member 41. Furthermore, a linker film 22 is formed on the upper surface (sensor surface 13 a) of the metal film 13 at a site corresponding to each flow path 16. Engaging claws 14 a that engage with the engaging portions 42 a of the holding member 42 are provided on both side surfaces of the prism 14 in the longitudinal direction. By these engagements, the flow path member 41 is sandwiched between the holding member 42 and the prism 14, and is held in a state where the bottom surface and the top surface of the prism 14 are in pressure contact with each other. Thus, the flow path member 41, the metal film 13, and the prism 14 are integrated.

  In addition, protrusions 14 b are provided at both ends in the short side direction of the prism 14. As will be described later, the sensor unit 12 is fixed in a state of being housed in a holder 52 (see FIG. 4). The protrusion 14 b is for positioning the sensor unit 12 at a predetermined storage position in the holder by fitting with the slit of the holder 52.

  The prism 14 is made of, for example, optical glass such as borosilicate crown (BK7) or barium crown (Bak4), polymethyl methacrylate (PMMA), polycarbonate (PC), amorphous polyolefin (APO), or the like. Representative optical plastics can be used.

  On the upper surface of the holding member 42, a receiving port 42b into which the tip of the pipette (19a, 19b, 26a, 26b) enters is formed at a position corresponding to the inlet 16a and the outlet 16b of each channel 16. The receiving port 42b has a funnel shape so that the liquid discharged from the pipette is guided to each inlet 16a. When the holding member 42 sandwiches the channel member 41 and engages with the prism 14, the lower surface of the receiving port 42 b is joined to the inlet 16 a and the outlet 16 b, and the receiving port 42 b and the channel 16 are connected.

  In addition, cylindrical bosses 42c are provided on both sides of each receiving port 42b. These bosses 42 c are for fitting the holes 43 a formed in the lid member 43 to position the lid member 43. The lid member 43 is affixed to the upper surface of the holding member 42 by a double-sided tape 44 having a hole in a position corresponding to the receiving port 42b and the boss 42c.

  The lid member 43 covers the receiving port 42 b communicating with the flow path 16, thereby preventing the liquid in the flow path 16 from evaporating. The lid member 43 is formed of, for example, an elastic material such as rubber or plastic, and a cross-shaped slit 43b is formed at a position corresponding to each receiving port 42b. Since the lid member 43 is for preventing evaporation of the liquid in the flow path 16, it is necessary to cover the receiving port 42b, but if it is completely covered, the pipette is inserted into the receiving port 42b. I can't. Therefore, by forming the slit 43b, the pipette can be inserted, and the receiving port 42b is closed when the pipette is not inserted. When the pipette is pushed into the slit 43b, the periphery of the slit 43b is elastically deformed (see FIG. 1), and the mouth of the slit 43b is wide open to receive the pipette. Then, when the pipette is pulled out, the slit 43b returns to the initial state by the elastic force and closes the receiving port 42b.

  For example, an RFID (Radio Frequency IDentification) tag that is a non-contact type IC tag may be attached to the prism 14 or the holding member 42 of the sensor unit 12. For example, the sensor unit 12 can be identified by writing a unique ID number for each sensor unit 12 in a read-only RFID tag and reading this ID number before performing each process. Thereby, even when fixing and measuring the plurality of sensor units 12 at the same time, it is possible to prevent the occurrence of problems such as erroneous injection of analytes and mistaken measurement results. Furthermore, using a readable / writable RFID tag, for example, the type of immobilized ligand, the date and time when the ligand was immobilized, and the type of analyte reacted may be written for each step. .

  As shown in FIG. 4, in the fixing machine 10, a mounting space 51 for mounting a plurality of sensor units 12 is secured on a housing base 50 that is a base of the housing. The sensor unit 12 is subjected to all the fixing processes while being placed in the placement space 51. Accordingly, the mounting space 51 serves as a fixed stage that performs a fixing process on the sensor unit 12.

  The sensor unit 12 is set in the fixing machine 10 while being accommodated in the holder 52. The holder 52 can accommodate a plurality of (for example, eight) sensor units 12. The holder 52 is provided with a slit for positioning the sensor unit 12 by fitting with the protrusion 14 b of the sensor unit 12. Further, the bottom of the holder 52 is an opening except for support portions that support both ends of the sensor unit 12. In the measurement process, when the sensor unit 12 is taken out from the holder 52, a push-up member is inserted from the opening and the sensor unit 12 is pushed up from below.

  In the mounting space 51, for example, ten holders 52 can be arranged side by side, and pedestals 53 corresponding to the number of the holders 52 are provided. On each pedestal 53, a positioning boss for positioning the holder 52 is provided.

  The fixing machine 10 is provided with a pipette head (dispensing head) 54 in which three pipette pairs 19 are connected in series. The pipette head 54 accesses the sensor units 12 arranged in the placement space 51 to inject and discharge liquid. Since three pipette pairs 19 are provided in the pipette head 54, liquid can be injected (and discharged) simultaneously into the three sensor cells 17 included in one sensor unit 12. The fixed machine 10 is provided with a controller (control unit) 60 that comprehensively controls each part of the fixed machine 10, and the controller 60 sucks and discharges each pipette pair 19 as well as the amount and volume of the suction. The amount is controlled.

  The housing base 50 is provided with a head moving mechanism 56 that moves the pipette head 54 in three directions of X, Y, and Z. The head moving mechanism 56 is a known moving mechanism including, for example, a conveyance belt, a pulley, a carriage, and a motor. The head moving mechanism 56 moves up and down the pipette head 54, and moves the pipette head 54 in the Y direction together with the lifting mechanism. A Y-direction moving mechanism including a guide rail 58 that is freely held, and an X-direction moving mechanism that holds the guide rail 58 at both ends and moves the pipette head 54 together with the guide rail 58 in the X direction. The head moving mechanism 56 is controlled by a controller 60, and the controller 60 drives the head moving mechanism 56 to control the front / rear / left / right / up / down positions of the pipette head 54.

  A plurality of liquid storage units 61 for storing various liquids (ligand solution, cleaning liquid, fixing buffer liquid, anti-drying liquid, activation liquid, blocking liquid, etc.) injected into the flow path 16 on the housing base 50. Is provided. The number of the liquid storage units 61 is determined according to the type of liquid to be used. Each liquid storage unit 61 is provided with six insertion ports arranged side by side. The number of the insertion openings and the arrangement pitch are determined according to the number of pipettes of the pipette head 54 and the arrangement pitch. When injecting liquid into the sensor cell 17, the pipette head 54 accesses each liquid storage unit 61 to suck in a desired liquid, and then moves to the placement space 51 and injects it into the sensor unit 12.

  On the housing base 50, a pipette tip storage unit 63 for storing a plurality of pipette tips 62 and an adjustment jig 64 for adjusting the amount of insertion of the pipette tips 62 are provided. The pipette tip 62 formed in a substantially conical cylinder shape is detachably held by the pipette head 54. That is, each pipette 19a, 19b is configured by attaching the pipette tip 62 to the pipette head 54. Since the pipette tip 62 is in direct contact with the liquid, the pipette tip 62 is exchanged for each liquid to be used so that a mixture of different kinds of liquids does not occur through the pipette tip 62.

  As shown in FIG. 5, the pipette head 54 is formed with a nozzle 54 a that performs suction and discharge of liquid according to pressure applied by a pump (not shown). The nozzle 54a is formed so as to protrude from the end face of the pipette head 54 in a substantially cylindrical shape, and its outer diameter and the inner diameter of the pipette tip 62 are substantially matched. When the pipette tip 62 is inserted into the nozzle 54a, it is held by the pipette head 54 by mechanical fitting with the nozzle 54a. FIG. 5 is a partial sectional view for explanation in which the pipette head 54 and the adjustment jig 64 in FIG. 4 are cut in the Y direction, and six nozzles 54a are formed along the X direction.

  The pipette head 54 is provided with a release mechanism (not shown). The release mechanism pushes down each pipette tip 62 inserted into each nozzle 54 a to remove each pipette tip 62 from the pipette head 54. When exchanging the pipette tips 62, first, the used pipette tips 62 are released by a discarding unit (not shown), and then the pipette tip storage unit 63 is accessed to replace the unused pipette tips 62 with each nozzle. 54a is inserted.

  The adjustment jig 64 is formed with six (see FIG. 4) adjustment holes 70 corresponding to the pipette tips 62 held by the pipette head 54. The hole depth of each adjustment hole 70 is substantially equal to the length of the pipette tip 62, and the hole diameter is slightly larger than the outer diameter of the pipette tip 62. The arrangement pitch of the adjustment holes 70 corresponds to each of the six pipette tips 62 attached to the pipette head 54. When the pipette head 54 inserts each pipette tip 62 into each adjustment hole 70, the adjustment jig 64 contacts the tip 62 a of each pipette tip 62 and the bottom surface 70 a of each adjustment hole 70 as shown in FIG. 6. Make contact.

  The position control of the pipette head 54 is performed by the controller 60 as described above. The controller 60 controls the amount of movement of the lifting mechanism of the head moving mechanism 56 to lower the pipette head 54 to a predetermined position where the tip 62a is pressed against the bottom surface 70a. As a result, the pipette tip 62 that is shallowly inserted into the nozzle 54a is pushed in, and the amount of insertion of each pipette tip 62 is adjusted to be constant.

  Each adjustment hole 70 is provided with a transmissive photo interrupter (pipette detection means) 71 including a light emitting element 72 and a light receiving element 73 arranged to face each other. The detection light emitted by the light emitting element 72 is blocked by the pipette tip 62 inserted into the adjustment hole 70. The photo interrupter 71 detects whether or not the pipette tip 62 is inserted by detecting that the detection light is blocked by the light receiving element 73. This detection result is transmitted to the controller 60.

  Returning to FIG. 4, in addition to the above, a well plate 65 in which a plurality of well-shaped ridges are arranged in a matrix is provided on the housing base 50. The well plate 65 is used for temporarily storing the liquid sucked up by the pipettes 19a and 19b, or for adjusting a mixed liquid by mixing plural kinds of liquids.

  When fixing is started, the casing of the fixing machine 10 is covered with a cover (not shown), and the inside of the fixing machine 10 including the placement space 51 is shielded from the outside. The temperature in the fixing machine 10 can be adjusted by a temperature controller (not shown). After the ligand 21a is injected into the sensor cell 17, the sensor unit 12 is stored on the mounting space 51 for a predetermined time until the ligand 21a is fixed to the sensor surface 13a. During this storage, the ligand solution 21 in the flow path 16 is stirred as necessary. The degree of progress of immobilization during this period depends on the environmental conditions (temperature, etc.) of the sensor unit 12. Therefore, the internal temperature of the fixing machine 10 is kept at a predetermined temperature by the temperature controller. The set temperature, standing time, and the like are appropriately determined according to the type of the ligand 21a.

  When the fixing is completed, a buffer (cleaning liquid) is injected into the sensor cell 17. The buffer is injected into the sensor cell 17 by inserting the pipette 19 a sucking the buffer into the slit 43 b while the sensor cell 17 is filled with the ligand solution 21. When the buffer is discharged from the injection port 16a to the flow channel, the ligand solution 21 already injected into the flow channel 16 is pushed out toward the discharge port 16b and discharged. Then, the buffer to be discharged is sucked by the pipette 19b that performs the suction operation in conjunction with the injection operation of the pipette 19a. Thereby, replacement (replacement) of the liquid in the sensor cell 17 is performed.

  After the cleaning is completed, a drying prevention liquid for preventing the ligand 21a from drying may be injected into the sensor cell 17 by the same procedure as described above. This prevents the ligand from drying out until the measurement is started.

  Next, the operation of the fixing machine 10 having the above configuration will be described with reference to the flowchart shown in FIG. When performing the fixing process on the sensor unit 12, first, the sensor unit 12 is accommodated in the holder 52, and the holder 52 is set in the placement space 51. After the sensor unit 12 is set, when a fixing start instruction is input from the operator, the pipette head 54 starts moving toward the pipette tip storage unit 63. The pipette head 54 moved to the pipette tip storage unit 63 inserts each nozzle 54 a into the stored pipette tip 62 and attaches the pipette tip 62. The pipette head 54 to which the pipette tip 62 is attached moves to the adjustment jig 64. The moved pipette head 54 inserts each pipette tip 62 into each adjustment hole 70 and presses the tip 62a of each pipette tip 62 against the bottom surface 70a of each adjustment hole 70 (see FIG. 6).

  At this time, the controller 60 confirms the detection result of the photo interrupter 71 provided in each adjustment hole 70 and determines whether or not the pipette tip 62 is inserted into each nozzle 54 a of the pipette head 54. When the controller 60 determines that the pipette tip 62 is not inserted into any one of the nozzles 54a, for example, the operation is stopped, the abnormality is notified to the operator, and the pipette tip 62 is released once. Then, abnormality detection processing such as reattaching the pipette tip 62 is executed.

  Each pipette tip 62 pressed against the bottom surface 70a is pushed into each nozzle 54a according to the downward movement amount of the pipette head 54, and is adjusted so that the amount of insertion into each nozzle 54a is constant. Variations in the amount of insertion caused by distortion of the storage unit 63 can be suppressed. Further, since the hole diameter of each adjustment hole 70 is slightly larger than the outer diameter of the pipette tip 62, the pipette tip 62 is adjusted when the pipette tip 62 is inserted obliquely with respect to the nozzle 54a. The direction of the pipette tip 62 can be straightened along the inner wall surface of the hole 70.

  The bottom surface 70a is orthogonal to the insertion direction of the pipette tip 62, and when the tip 62a is pressed, a uniform force is applied to the pipette tip 62 with respect to the insertion direction. Accordingly, it is possible to prevent the pipette tip 62 from being inclined by being pressed against the bottom surface 70a or the pipette tip 62 from being fitted into the adjustment hole 70 and being removed from the nozzle 54a.

  After this, the pipette head 54 moves to the adjustment jig 64, and each pipette tip 62 is inserted into each adjustment hole 70 so that the tip 62a of each pipette tip 62 and the bottom surface 70a of each adjustment hole 70 are in contact with each other. A series of operations until contact is made is referred to as “pushing the pipette tip 62”.

  The pipette head 54 that carefully presses each pipette tip 62 moves to the liquid storage section 61 that stores the activation liquid of the linker film 22, and causes each pipette 19a to suck the activation liquid. The pipette head 54 that has sucked the activation liquid moves toward the sensor unit 12 set in the placement space 51. The pipette head 54 that has moved to the sensor unit 12 injects an activation liquid into each flow path 16 of the sensor unit 12 and applies an activation process to each linker film 22.

  At this time, each pipette tip 62 is carefully pushed and adjusted so that the amount of insertion into the nozzle 54a is constant, so that the pipette tip 62 is left stuck in the flow path 16 through the nozzle 54a. The trouble that the inserted pipette tip 62 moves the sensor unit 12 to cause disturbance in the SPR signal is prevented. In addition, since it is detected whether or not the pipette tip 62 is inserted by the photo interrupter 71, there is no problem that the fixing process proceeds without the pipette tip 62 attached.

  The pipette head 54 infused with the activation liquid moves to a discarding section (not shown), and releases each pipette tip 62 immersed in the activation liquid to the disposal section. The pipette head 54 that has released each pipette tip 62 moves again to the pipette tip storage section 63 to attach the pipette tip 62, moves to the adjustment jig 64, performs a careful push on each pipette tip 62, and then injects. Replace pipette tip 62 for ligand solution 21. When each pipette tip 62 is released, each pipette tip 62 may be returned to the pipette tip storage unit 63 and a dedicated pipette tip 62 may be provided for each liquid to be injected.

  The pipette head 54 that has exchanged the pipette tip 62 moves to the liquid storage unit 61 that stores the ligand solution 21, and causes each pipette 19a to aspirate the ligand solution 21. The pipette head 54 that has aspirated the ligand solution 21 moves toward the sensor unit 12 set in the placement space 51. The pipette head 54 that has moved to the sensor unit 12 injects the ligand solution 21 into each flow path 16 of the sensor unit 12 and performs an immobilization process for fixing the ligand 21 a to each linker film 22.

  In the above embodiment, the bottom surface 70a of the adjustment hole 70 is the abutting surface according to claim 5. However, the present invention is not limited to this, and for example, as shown in FIG. 8, a pipette tip having a stepped portion 80a is formed. When 80 is used, the insertion amount may be adjusted using the upper surface 64a of the adjustment jig 64 as the contact surface. Further, when there is no concern that the pipette tips 62, 80 are inserted obliquely with respect to the nozzle 54a, the pipette tips 62, 80 are arranged on a simple plane perpendicular to the insertion direction without providing the adjustment jig 64. The amount of insertion may be adjusted by pressing the tips 62a and 80b of the 80.

  Moreover, in the said embodiment, although the substantially conical cylindrical pipette tips 62 and 80 are used, the shape of a pipette tip is not restricted to this, For example, a triangular pyramid shape or a quadrangular pyramid shape may be sufficient. . Further, the adjustment hole 70 is formed in a cylindrical shape in accordance with the conical cylindrical pipette tips 62, 80, but this shape is not limited to this, and the pipette tip shape is adjusted according to the shape of the pipette tip. The shape may be at least partially insertable.

  In the above embodiment, the transmissive photointerrupter 71 is used as the pipette detection means. However, the present invention is not limited to this, and other optical sensors such as a reflective photointerrupter may be used. A sensor or a mechanical switch may be used. Further, for example, by providing protrusions on the pipette tips 62 and 80 and detecting their predetermined positions (heights), the insertion amount of the pipette tips 62 and 80 may be detected. .

  Moreover, in the said embodiment, although the pressing means of a claim is comprised by the head moving mechanism 56 and the controller 60, it is not restricted to this, For example, the adjustment jig 64 side is moved, A mechanism for inserting the pipette tips 62 and 80 into the adjustment hole 70 may be used.

  Furthermore, in the above-described embodiment, the prism 14 is shown as the dielectric block. However, the dielectric block may be a plate made of optical glass, optical plastic, or the like, or those plate-like ones. What integrated the prism with the optical surface smoothing agent (for example, optical matching oil) shall be included.

  In the above-described embodiment, an example in which the fixing jig 64 is provided in the fixing machine 10 and each pipette pair 19 of the fixing machine 10 is carefully shown is shown, but of course, the adjustment jig 64 is provided in the measuring machine 11, You may make it press the pipette pair 26 of the measuring machine 11 carefully. Furthermore, you may apply this invention to the other dispensing apparatus which inserts and uses a pipette tip.

  In the above embodiment, an SPR measurement device is shown as an example of a measurement device using total reflection attenuation. However, for example, a leakage mode sensor is known as a measurement device using total reflection attenuation. ing. The leakage mode sensor is composed of a dielectric, and a thin film composed of a clad layer and an optical waveguide layer that are sequentially layered thereon. One surface of the thin film serves as a sensor surface, and the other surface receives light. It becomes a surface. When light is incident on the light incident surface so as to satisfy the total reflection condition, a part of the light is transmitted through the cladding layer and taken into the optical waveguide layer. In this optical waveguide layer, when the waveguide mode is excited, the reflected light at the light incident surface is greatly attenuated. The incident angle at which the waveguide mode is excited changes according to the refractive index of the medium on the sensor surface, similar to the resonance angle of SPR. By detecting the attenuation of the reflection angle, the chemical reaction on the sensor surface is measured.

It is explanatory drawing of a SPR measuring method. It is explanatory drawing which extracts and demonstrates one sensor cell. It is a disassembled perspective view which shows schematic structure of a sensor unit. It is a perspective view which shows the structure of a fixing machine roughly. It is explanatory drawing which shows the state before a pipette tip is inserted in an adjustment jig. It is explanatory drawing which shows the state by which the pipette tip was inserted in the adjustment jig. It is a flowchart which shows the procedure of an immobilization process. It is explanatory drawing which shows the other example of insertion amount adjustment.

Explanation of symbols

10 Fixing Machine 11 Measuring Machine 12 Sensor Unit 13 Metal Film (Thin Film Layer)
14 Prism (dielectric block)
32 Illumination part 33 Detector (light detection means)
34 Light source 54 Pipette head (dispensing head)
54a Nozzle 56 Head moving mechanism 60 Controller (control unit)
62, 80 Pipette tips 62a, 80b Tip 64 Adjustment jig 64a Top surface 70 Adjustment hole 70a Bottom surface

Claims (8)

In a dispensing apparatus having a dispensing head that forms a nozzle for sucking and discharging liquid, and detachably holds a substantially cylindrical pipette tip inserted into the nozzle.
An adjustment jig in which an adjustment hole into which at least a part of the pipette tip is inserted, and an abutment surface substantially orthogonal to the insertion direction of the pipette tip;
2. A dispensing apparatus comprising: a pressing unit that inserts the pipette tip held by the dispensing head into the adjustment hole and presses a part of the pipette tip against the contact surface.   2. The dispensing apparatus according to claim 1, further comprising pipette detection means for detecting whether or not the pipette tip is inserted into the adjustment hole. A plurality of the nozzles are formed in the dispensing head,
The dispensing apparatus according to claim 1 or 2, wherein the adjustment jig has a plurality of adjustment holes according to the number of the plurality of pipette tips inserted into the plurality of nozzles.   The pressing unit includes a head moving mechanism that moves the dispensing head in three directions, front, rear, left, right, and up, and a control unit that controls the amount of movement of the head moving mechanism in each direction. Item 4. The dispensing device according to any one of Items 1 to 3. The contact surface is a bottom surface of the adjustment hole,
The dispensing device according to any one of claims 1 to 4, wherein the pressing means presses the tip of the pipette tip against the bottom surface. A pipette tip mounting method for a dispensing device having a dispensing head that detachably holds a substantially cylindrical pipette tip that is inserted into the nozzle, and that forms a nozzle that sucks and discharges liquid.
After inserting the pipette tip into the nozzle,
Press the pipette tip against the contact surface substantially perpendicular to the insertion direction of the pipette tip,
A pipette tip mounting method comprising adjusting an amount of the pipette tip inserted into the nozzle.   The pipette tip mounting method according to claim 6, wherein when the pipette tip is pressed against the contact surface, a uniform force is applied to the pipette tip in the insertion direction. For a sensor unit comprising a dielectric block having a thin film layer formed on one surface and a flow path member having a flow path for supplying a sample solution to the thin film layer, light is transmitted so as to satisfy the total reflection condition. In a measuring device using total reflection attenuation, comprising: a light source that irradiates light; and a light detection means that receives reflected light from the sensor unit and photoelectrically converts it into an electrical signal
A nozzle for forming and sucking the sample solution is formed, and a dispensing head for detachably holding a substantially cylindrical pipette tip inserted into the nozzle is used to inject the sample solution into the channel. Means,
An adjustment jig in which an adjustment hole into which at least a part of the pipette tip is inserted, and an abutment surface substantially orthogonal to the insertion direction of the pipette tip;
Utilizing total reflection attenuation, wherein the pipette tip held by the dispensing head is inserted into the adjustment hole, and a pressing means for pressing a part of the pipette tip against the contact surface is provided. Measuring device.

Images