JP2011017568A - Liquid volume measuring instrument and gene autoanalyzer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid volume measuring instrument in which air existing between a plunger and a liquid is prevented from affecting suction or discharging of a trace liquid, when making the measuring instrument constitute a nozzle tip of only one kind.SOLUTION: The liquid volume measuring instrument includes the plunger 1 for sucking or discharging a liquid by reciprocating movement, the nozzle tip 3 containing the liquid sucked by the plunger 1, and a nozzle 2 for therein holding the nozzle tip 3. The volume of air existing between the plunger 1 and the liquid is reduced, by providing a member 5 having a prescribed volume in the nozzle tip 3, in order to reduce a liquid-containing space in the nozzle tip 3.

Description

  The present invention relates to a liquid measuring device that sucks and discharges while measuring a certain amount of liquid and an automatic gene analyzer equipped with the same.

  A liquid metering device that sucks and discharges while measuring a certain amount of liquid, attaches a nozzle tip to the nozzle tip, draws a certain amount of plunger, sucks a certain amount of liquid, and pushes the plunger a certain amount to keep it constant The amount of liquid is discharged. However, in this method, since air exists between the plunger and the liquid, the compression of the air affects the accuracy when a small amount of liquid is sucked and discharged.

  As one means for solving this problem, there is a method of using a chip having a small capacity corresponding to the amount of liquid when a small amount of liquid is sucked and discharged. By reducing the amount of air in the chip in advance and reducing the influence of air compression, highly accurate suction and discharge can be performed. However, when both a large amount of liquid suction / discharge and a small amount of liquid suction / discharge are performed by one liquid metering device, two types of nozzle chips are used separately, which complicates the configuration.

  As another means for solving this problem, for example, as described in Patent Document 1, there is a method of reducing air by causing a plunger to protrude inside the chip.

JP 2004-325170 A

However, the technique disclosed in Patent Document 1 has the following three problems.
(1) Since the object that fills the air volume in the chip is a plunger, it cannot be shaped to impede the function of the plunger. For example, since a certain thickness is necessary for securing the strength of the fitting portion for inserting the tip, a large-diameter plunger approaching just before the inner wall of the tip cannot be used, and a large air layer remains. Further, since the plunger tip usually returns to the inside of the syringe, it is not possible to enlarge only the plunger tip.
(2) Also, the plunger must be thin to increase the dispensing volume resolution. If the amount of suction is large compared to the required resolution, the Matsushita patent method does not fill the air volume. Or you need a very long and thin tip and plunger.
(3) Since there is no structure or dimension limitation for preventing liquid contact, liquid contact between the suction liquid and the plunger can be a problem. It is impossible to avoid contamination of the plunger and syringe due to liquid scattering and evaporation during suction.

  The present invention provides a liquid metering device having a plunger that sucks and discharges liquid by a reciprocating motion, a nozzle tip that stores the liquid sucked by the plunger, and a nozzle that holds the nozzle tip. A member having a predetermined volume is provided to reduce the space for storing the liquid in the nozzle tip.

  The liquid metering device of the present invention is composed of one kind of nozzle tip, and by providing a chip with a volume in the tip, the air between the plunger and the liquid is reduced, and a minute amount of liquid is sucked with high accuracy.・ Can be discharged.

2 is a liquid metering device according to the first embodiment. Liquid metering device for sucking and discharging a large amount of liquid. 2 is a liquid metering device according to a second embodiment. 3 is a liquid metering device according to a third embodiment. 4 is a liquid metering device according to a fourth embodiment.

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

  An outline of the liquid metering apparatus according to the first embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, the liquid metering apparatus of the first embodiment has a plunger 1, a nozzle 2, a nozzle tip 3, a first filter 4, and a device 5 having a first volume. The plunger 1 reciprocates to suck and discharge liquid.

  The nozzle tip 3 is held by the nozzle 2 and the sucked liquid is temporarily stored in the nozzle tip 3. The nozzle chip 3 is composed of a first filter 4 for preventing contamination and a filter 5 having a first volume. The first filter 4 is made of a porous material and allows air to pass through. The thing 5 which has a 1st volume is porous, for example, is a cone shape, and provides the passage of air by providing a hole in the center. The one having the first volume 5 can reduce the amount of air by the volume, so that high-accuracy suction / discharge can be performed.

  FIG. 2 shows a liquid metering device for sucking and discharging a large amount of liquid. As shown in FIG. 2, the liquid metering device for sucking and discharging a large amount of liquid has a plunger 1, a nozzle 2, a nozzle tip 3, and a second filter 6. The plunger 1 reciprocates to suck and discharge liquid. The nozzle tip 3 is held by the nozzle 2 and the sucked liquid is temporarily stored in the nozzle tip 3. The nozzle chip 3 includes a second filter 6 for preventing contamination. By sharing the nozzle tip 3, the liquid metering device can be configured with only one kind of nozzle tip.

  An outline of the liquid metering apparatus according to the second embodiment of the present invention will be described with reference to FIG. As shown in FIG. 3, the liquid metering device of the second embodiment includes a plunger 1, a nozzle 2, a nozzle tip 3, a third filter 7, and a device 8 having a second volume. The plunger 1 reciprocates to suck and discharge liquid. The nozzle tip 3 is held by the nozzle 2 and the sucked liquid is temporarily stored in the nozzle tip 3. The nozzle tip 3 is composed of a third filter 7 for preventing contamination and a filter 8 having a second volume.

  The third filter 7 is made of a porous material and allows air to pass through. The thing 8 which has a 2nd volume is conical shape, and provides the passage of air by providing a hole in the center. The difference from the first embodiment is the positional relationship between the filter and the volume. The thing 8 having the second volume can reduce the amount of air by the volume, so that high-accuracy suction / discharge can be performed.

  An outline of the liquid metering apparatus according to the third embodiment of the present invention will be described with reference to FIG. As shown in FIG. 4, the liquid metering apparatus according to the third embodiment includes a plunger 1, a nozzle 2, a nozzle tip 3, and a fourth filter 9. The plunger 1 reciprocates to suck and discharge liquid. The nozzle tip 3 is held by the nozzle 2 and the sucked liquid is temporarily stored in the nozzle tip 3. The nozzle chip 3 is composed of a fourth filter 9 for preventing contamination. The fourth filter 9 is made of a porous material and has a larger size than usual and reduces the amount of air. However, simply increasing the resistance increases the resistance and affects the accuracy. Therefore, it is improved by increasing the pore size of the filter and reducing the resistance.

  An outline of the liquid metering apparatus according to the fourth embodiment of the present invention will be described with reference to FIG. As shown in FIG. 5, the liquid metering apparatus according to the fourth embodiment includes a plunger 1, a nozzle 2, a nozzle tip 3, and a device 10 having a third volume. The plunger 1 reciprocates to suck and discharge liquid. The nozzle tip 3 is held by the nozzle 2 and the sucked liquid is temporarily stored in the nozzle tip 3. The nozzle tip 3 is composed of one having a third volume. The thing 10 which has a 3rd volume is conical shape, and provides the passage of air by providing a hole in the center. The difference from the first embodiment is that there is no filter for preventing contamination. By having the third volume 10 reduce the amount of air by the volume, high-accuracy suction / discharge can be performed.

  According to the present invention, the following effects can be obtained as compared with Patent Document 1 described above.

  In the present invention, since the shape has a high degree of freedom in shape, it is possible to fill the partial volume up to the inner wall of the chip on the fitting portion, and the volume reduction effect is great. Therefore, the dispensing accuracy is further improved. In particular, this effect is significant at the center side of the circle and the donut-shaped portion around it because the area of the donut-shaped portion is relatively large due to the large radius.

  In addition, since the present invention inserts a filter or inserts a filter having a volume when the filter alone is insufficient, it is possible to avoid contamination of the plunger or syringe due to liquid scattering or evaporation during suction. it can. This is an essential function especially for molecular biology such as genes.

  The present invention can also be expressed as follows.

  The present invention provides a liquid metering device having a reciprocating plunger, a nozzle tip for holding liquid, and a nozzle for holding the nozzle tip, and by providing a nozzle tip having a volume, the plunger and liquid The volume of air between the two is reduced.

  Further, the present invention provides a liquid metering device having a reciprocating plunger, a nozzle tip for holding liquid, and a nozzle for holding the nozzle tip, wherein the volume has a conical shape and has a hole in the center. It is characterized by.

  Further, the present invention is a liquid metering device having a plunger that reciprocates, a nozzle tip that holds liquid, and a nozzle that holds the nozzle tip, wherein the one having the volume is porous and air can pass therethrough. .

DESCRIPTION OF SYMBOLS 1 Plunger 2 Nozzle 3 Nozzle tip 4 1st filter 5 What has 1st volume 6 2nd filter 7 3rd filter 8 What has 2nd volume 9 4th filter 10 It has 3rd volume thing

Claims (8)

In a liquid metering device having a plunger that sucks and discharges liquid by reciprocating motion, a nozzle tip that stores the liquid sucked by the plunger, and a nozzle that holds the nozzle tip,
A liquid metering device, wherein a member having a predetermined volume is provided in the nozzle tip so as to reduce a storage space for the liquid in the nozzle tip. Claim 1 wherein
The member having the predetermined volume has a conical shape and has a hole in the center thereof. Claim 1 wherein
The liquid metering device, wherein the member having the predetermined volume is formed of a porous material. Claim 1 wherein
In the nozzle tip, a contamination preventing filter is provided on the plunger side of the member having the predetermined volume. Claim 1 wherein
In the nozzle tip, a contamination preventing filter is provided on a side opposite to the plunger side of the member having the predetermined volume. Claim 1 wherein
The nozzle tip is removable;
A liquid metering device, wherein when a larger amount of liquid is sucked and discharged, the liquid metering device can be replaced with another nozzle chip provided only with a filter for preventing contamination. Claim 1 wherein
Part of the nozzle tip is formed of a filter for preventing contamination, and a liquid measuring device. In a gene automatic analyzer using a plunger that sucks and discharges liquid by reciprocating movement, a nozzle chip that stores liquid sucked by the plunger, and a liquid metering device that has a nozzle that holds the nozzle chip,
An automatic gene analyzer according to claim 1, wherein a member having a predetermined volume is provided in the nozzle chip so as to reduce a storage space for the liquid in the nozzle chip.

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