JP2015190855A - Device and method for controlling the amount of reagent to be injected in microchip - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique to inject a reagent in a microchip passage each time at a constant amount.SOLUTION: The device and method for performing biochemical analysis comprise an installation part on which a microchip is installed, a nozzle part for injecting a reagent in an inlet of the microchip, a reagent discharge part for discharging or sucking the reagent, a detection part for detecting the end edge of an injected liquid in the microchip, and a control part for controlling the discharge and sucking amount of the reagent discharge part on the basis of information obtained by the detection part. When the reagent is injected in the microchip, if a position of the end edge of the injected liquid in a microchip main passage, which is detected by the detection part, exceeds a proper position, the injected liquid is sucked by decompressing the reagent discharge part to return the position of the end edge of the injected liquid to the proper position, and if the position of the end edge of the injected liquid in the microchip passage does not reach the proper position, the injected liquid is increased by additionally compressing the reagent discharge part to control the position of the end edge of the injected liquid to reach to the proper position.

Description

  The present invention relates to an apparatus and a method for injecting a reagent with an optimal amount of liquid into a microchip reagent channel.

  In genetic analysis operations used in the life science field in recent years, a specimen sample is injected into a microchip that has been immobilized in advance by a method such as applying a reaction reagent to a well (reaction chamber) and drying and solidifying the microchip. Means for performing amplification reaction and detection of DNA in the well are often used.

  Injecting a specified amount of a reagent in the order of several microns into such a microchip into such a microchip has characteristics such as the viscosity of the reagent to be injected, the shape and surface resistance of the microchip, and an injection mechanism such as an air syringe. Many factors influence and it is very difficult to properly control the injection amount (dispensing amount).

Therefore, a method of making the flow rate constant intentionally by changing the temperature of the liquid flowing through the microchip fine flow path as in Patent Document 1 is considered.

However, the microchip as described in Patent Document 1 needs to form a thermal resistor on a film covering the microchannel of the microchip, and for such a microchip that becomes a disposable (disposable), The cost and labor for forming the resistor are problematic.

In addition, even with the flow rate control method described in Patent Document 1, high accuracy is required for heat transfer control to the liquid flowing in the fine flow path. After all, instead of the flow rate control, this time the heat transfer control is performed. It is necessary to pay attention to the control, and an apparatus load is also applied.

JP 2009-229208 A

An object of the present invention is to optimize the amount of reagent injected into a microchip and a microchip well by more easily realizing the flow control into the microchip channel.

The present invention provides an installation part for installing a microchip, a nozzle part for injecting a reagent into the microchip injection port, and a reagent discharge part for discharging and aspirating the reagent in order to optimize the amount of liquid injected into the microchip And a reagent injection amount control apparatus and method comprising: a detection unit that detects a terminal end of an injection solution of the microchip; and a control unit that controls a discharge / aspiration amount for the reagent discharge unit based on information obtained by the detection unit About.

According to the reagent injection control apparatus and method for a microchip in the present invention, it is possible to inject an appropriate amount of reagent into the microchip reagent flow path, and as a result, filling the amount of reagent injection into the microchip well. It is possible to suppress the decrease in DNA amplification reactivity due to the shortage and the risk of reagent protrusion from the microchip reagent inlet and the air hole.
As a result, it is possible to prevent a decrease in DNA amplification reactivity and prevent a reagent from protruding from the microchip (overflow, etc.), and perform an appropriate reaction.

The apparatus block schematic diagram in this invention. The state outline figure at the time of the reagent injection liquid lack to a microchip. The state outline figure at the time of the reagent injection liquid excess to a microchip.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

  FIG. 1 shows a schematic diagram of the apparatus configuration in the present invention.

The nozzle unit 3 in the present invention includes, for example, a pipette arm that can be driven on one or both of the X-axis and Y-axis parallel to the horizontal plane and can be driven on the Z-axis perpendicular to the horizontal plane. It is desirable to attach a disposable dispensing pipette tip.
In addition, the mounting unit 1 may move in the X-axis, Y-axis, and Z-axis directions. Furthermore, the form which both the pipette arm (nozzle part 3) and the mounting part 1 move to arbitrary axial directions may be sufficient.

In the present invention, the reagent discharge unit 5 is preferably connected to the nozzle unit 3 through a pipe and includes an air syringe and a stepping motor that drives the syringe.
The discharge part of this application is an example using an air syringe. When the pressure of the air syringe is increased (additional pressure), the reagent is discharged from the air syringe and the liquid is added to the microchip.
On the other hand, when the pressure of the air syringe is decreased (decompressed), the reagent is sucked into the air syringe (sucked), thereby reducing the amount of liquid in the microchip.

  The detection unit 7 in the present invention is preferably provided with a CCD camera and detects the injection liquid end position in the microchip flow path based on the image captured by the camera.

In the present invention, when the injection liquid end position detected by the detection unit 7 exceeds the pre-stored microchip injection liquid end appropriate position, the control unit 9 depressurizes the reagent discharge unit 5 by a small amount to inject The liquid end position is returned to an appropriate position, and when the detected infusate end position does not reach the pre-stored microchip infusate end proper position, the reagent discharge unit 5 is subjected to a small amount of pressure to inject the infusate end position. It is desirable to control such that it reaches the proper position.

As for the proper end position of the injection solution, a mark may be provided on the surface of the microchip 11 to facilitate image recognition. The mark can be formed in a form rising from the surface of the microchip (projecting from the chip surface), a shape recessed from the surface of the microchip (concave shape), coloring, and the like, a form that can be easily recognized and visually recognized, and a color.
For example, the proper end position mark can be provided on either side of the flow path, provided on one side of the flow path, or on the upper part of the flow path, or can be colored. You may combine them.
When the microchip is manufactured from a resin, the mark is preferably formed at the same time as manufacturing the microchip from the viewpoint of manufacturing cost.

  The reagent injected from the reagent injection port 17 of the microchip into the main channel 12 is then sent to the microchip well 13 through the branch path 14 by centrifugal force (hereinafter sometimes referred to as centrifugal operation).

Here, taking a circular microchip as an example, FIG. 2 shows an outline of the state when the amount of reagent injected into the microchip channel is insufficient.
In FIG. 2 and FIG. 3, the injection liquid end position is schematically shown by a dotted line.

In such a case, when the injected reagent is sent to the microchip well 13 by centrifugal force, a part or all of the microchip well 13 is not filled with the injection solution, and as a result, there is a risk that the PCR amplification reactivity decreases. There is. When the PCR amplification reactivity is lowered, the target amplification reaction may not occur sufficiently and the reaction may fail.

Even in such a case, according to the present invention, since there is a step of detecting the injection liquid end position 15 by the detection unit 7, it is determined that the injection liquid end position 15 has not reached the appropriate position in the process, and the control unit The reagent is discharged from the microchip well 13 by the centrifugal operation by controlling the injection of the reagent to the proper end position so that the injecting liquid end position 15 reaches the proper position. It is possible to prevent such a situation that the reagent in the microchip well 13 is insufficient.

Similarly, taking a circular microchip as an example, FIG. 3 shows an outline of the state when the amount of reagent injected into the microchip channel is excessive.

In such a case, by applying temperature to the microchip 11 during the PCR amplification reaction, the reagent remaining in the main channel 12 and the branch channel 14 of the microchip expands in the channel, and as a result, the microchip reagent inlet 17 There is a risk that the reagent leaks out (overflows) from the air hole 19. In such a case, in a biochemical analyzer, contamination in the apparatus occurs, and there is a concern about the influence on the reaction system. Therefore, it is necessary to avoid such a state as much as possible.
The influence on the reaction system means that the reagent of the overflowing microchip remains in the apparatus, so that there is a possibility that the reaction does not occur correctly in another microchip.

Even in such a case, according to the present invention, since there is a step of detecting the injection liquid end position 15 by the detection unit 7, it is determined that the injection liquid end position 15 has exceeded the proper position in that process, and control is performed. The reagent discharge unit 5 is depressurized by a small amount from the unit 9 and controlled to return the injection liquid end position 15 to an appropriate position, whereby the inside of the microchip flow channel expands during the PCR amplification reaction. As a result, the microchip reagent inlet 17 Or a situation in which the reagent leaks from the air hole 19 can be prevented.

The proper position in the microchip channel differs depending on the shape and capacity of the microchip channel to be used, the surface treatment state, etc., so the appropriate position was examined in advance for each type of microchip and determined as a result. It is desirable to store the appropriate position in the detection unit 7 or the control unit 9.

  The apparatus and method for controlling the amount of reagent injected into a microchip according to the present invention can be used in a biochemical analyzer to make the amount of reagent injected into a microchip constant every time.

DESCRIPTION OF SYMBOLS 1 Microchip installation part 3 Nozzle part 5 Reagent discharge part 7 Detection part 9 Control part 11 Microchip 12 Main flow path 13 Well 14 Branching path 15 Injection liquid terminal position 17 Reagent injection port 19 Air hole

Claims (2)

An installation part for installing a microchip, a nozzle part for injecting a reagent into the microchip injection port, a reagent discharge part for discharging and aspirating the reagent, a detection part for detecting an injection liquid end of the microchip, and the detection Equipped with a control unit for controlling the discharge / aspiration amount with respect to the reagent discharge unit based on the information obtained in the unit,
When a reagent is injected into the microchip, if the end position of the injection liquid in the microchip main channel detected by the detection unit is too far from the appropriate position, the reagent discharge part is decompressed to suck the injection liquid Then, the injection liquid end position is returned to the appropriate position. Conversely, if the injection liquid end position in the microchip channel does not reach the proper position, the reagent discharge part is replenished to increase the injection liquid, and the injection A biochemical analyzer characterized by controlling the liquid end position to reach an appropriate position. An installation part for installing a microchip, a nozzle part for injecting a reagent into the microchip injection port, a reagent discharge part for discharging and aspirating the reagent, a detection part for detecting an injection liquid end of the microchip, and the detection Equipped with a control unit for controlling the discharge / aspiration amount with respect to the reagent discharge unit based on the information obtained in the unit,
When a reagent is injected into the microchip, if the end position of the injection liquid in the microchip main channel detected by the detection unit is too far from the appropriate position, the reagent discharge part is decompressed to suck the injection liquid Then, the injection liquid end position is returned to the appropriate position, and conversely, if the injection liquid end position in the microchip channel has not reached the appropriate position, the reagent discharge unit is repressed to increase the injection liquid, A control method, characterized by controlling the infusate terminal position so as to reach an appropriate position.

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