JP3152675B2 - Dispensing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dispensing method for quantitatively measuring the concentration of a chemical component in a sample such as blood or urine.

[0002]

2. Description of the Related Art Conventionally, this type of method is used, for example, for blood and blood.
It is applied to a dispensing device used for examining bodily fluids such as urine or a dispensing device used for examining water quality such as rivers and sewers. This kind of general dispensing apparatus is provided with a probe capable of sucking and discharging a sample and a syringe connected to the probe.

[0003] The portion from the pressurizing chamber of the syringe to the tip end of the probe is filled with, for example, incompressible extrusion water. For this reason, the pressurizing / depressurizing action of the syringe acts on the tip of the probe via the extruded water. As a result, a predetermined amount of sample (for example, blood or urine) can be sucked and discharged from the tip of the probe.

[0004] The dispensing apparatus to which such a dispensing method is applied has an air layer interposed between the extruded water and the sample so that the extruded water and the sample sucked in the probe do not mix. It is configured to be. Such a probe is washed with washing water prior to aspirating each sample in order to prevent contamination of the apparatus, contamination of the extruded water with the sucked sample, and the like (Japanese Patent Application Laid-Open No. 58-12936).
No. 6).

[0005]

However, the washing of the sample in the conventional dispensing method is not sufficient, and as a result, diseases such as viral hepatitis and acquired immunodeficiency cause the sample attached to the probe to be washed. There is a problem of contamination through the. Although it is conceivable to wash the probe for a long time, it is not a very effective method because an enormous amount of washing water is required.

In order to prevent the cleaning of the probe while preventing infection and contamination, a detachable (disposable) probe is attached to the tip of the probe body,
There is also a dispensing method in which an analysis liquid such as a sample or a reagent is dispensed (JP-A-2-243960, JP-A-2-174).
No. 48, JP-A-55-121150 and JP-A-58-216733), since a sample or the like is aspirated while the probe is filled with air, air is dispensed from the syringe. Exhibits pressure buffering and lacks quantitative performance. In addition, in the conventional dispensing method, for example, when dispensing a sample having a property of a surfactant such as a protein, an air layer separating the extruded water and the sample sucked into the probe is broken. Problem. That is, when the sample is discharged, there is a problem that the extruded water enters the sample through the gap between the probe inner wall and the air. As a result, there is a problem that contamination between the sample and the extrusion water is caused. When such contamination occurs, the amount of the sample to be dispensed fluctuates, so that highly accurate dispensing cannot be performed.

Further, in the conventional dispensing method, little consideration is given to contamination between the aspirated samples. In other words, in clinical chemistry tests, which have been the mainstream of conventional blood tests, the difference between the lowest value and the highest value in a test item is about 100 times. However, in the testing of infectious diseases that have recently attracted attention, the gap between the lowest and highest values is about 100,000 to 1,000,000 times. When this type of test is performed by a conventional clinical chemistry test method, there is a problem that the number of false positive determinations is significantly increased due to contamination between samples.

The present invention has been made under the above circumstances, and an object of the present invention is to prevent contamination of an analysis liquid by a short and low-cost operation . And high accuracy
Is to provide a dispensing method capable of performing a proper dispensing.

[0009]

In order to solve the above-mentioned problems, a dispensing method according to the present invention is directed to a dispensing method for dispensing a plurality of types of analysis liquids : a probe detachably attached to a tip of a probe body. a step of mounting a; sucks some of the air in the probe after the introduction of incompressible liquid; step and introducing to meet incompressible liquid into the probe after installation
To form the first air layer, and then suck the auxiliary liquid,
Further, a small amount of air is sucked to form a second air layer, and
Next, aspirate the liquid for analysis,
Analytical liquid, second air layer, auxiliary liquid, first air
Layer, and a step of configuring the incompressible liquid; a discharge step of quantitatively discharge the aspirated liquid for analysis; a step of leaving the probe from the distal end of the probe body after discharging process;
It is characterized by having.

[0010]

[0011]

The dispensing of the present invention for dispensing a plurality of types of liquids for analysis.
In the method, a detachable probe is mounted on the tip of the probe body, an incompressible liquid is introduced so as to fill the mounted probe, and some air is introduced into the probe after introducing the incompressible liquid. Is sucked to form the first air layer
The auxiliary liquid is then aspirated and a little more air
Is aspirated to form a second air layer and then for analysis
The liquid is aspirated and the analysis liquid,
A second air layer, an auxiliary liquid, a first air layer, and a non-
A compressible liquid is formed, after which the sucked analysis liquid is quantitatively discharged , and the probe is detached from the tip of the probe main body after the discharging step.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A dispensing method according to one embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a configuration of a dispensing apparatus to which the dispensing method of the present embodiment is applied.
Shown schematically.

As shown in FIG. 1, the dispensing apparatus includes a probe main body 2, a connection tube 4 extending from an upper end of the probe main body 2, and a syringe 6 connected to a distal end of the connection tube 4. Have. The probe main body 2 includes a tip 8 to which the connection tube 4 is connected, and a detachable probe 10 at a lower end of the tip 8. The tip 8 of the probe body 2 is supported by a first support portion 12, which slidably engages with a first guide portion 14 extending in the Z direction in the drawing. Have been. The guide portion 14 is supported by a second support portion 16, and the second support portion 16 is slidably engaged with a second guide portion 18 extending in the X direction in the drawing. I have. A base end portion 20 of the second guide portion 18 is slidably engaged with a third guide portion 22 extending in the Y direction in the drawing. Both ends of the third guide portion 22 are held by a pair of holding members 26 extending from the base 24 of the dispensing device in the Z direction in the drawing.

The connection tube 4 connects the pressurizing chamber of the syringe 6 (see Japanese Patent Application Laid-Open No. 58-129366) with the probe main body 2 and has an incompressible push water 7 (see FIG. 2) (for example, ion-exchanged water). As a result, the pressurizing / depressurizing action of the syringe 6 is
It acts directly on the tip of the probe 10 of the probe body 2 via the extruded water 7. A filling tube 28 extends from the pressurizing chamber of the syringe 6, and the filling tube 28 is provided with a pump 3 for filling the pushing water 7.
0 and an electromagnetic valve 32 for controlling the timing of the pumping water 7 pumped from the pump 30 are connected.

The base 24 is provided with a reaction vessel 36 provided with a plurality of reaction cells 34 and a detaching member 38 for detaching the probe 10 from the chip 8. The probe 10 detached by the detaching member 38 is
Is dropped and accommodated in the accommodating portion 40 arranged at the lower part of the cradle.
Further, the base 24 includes a container rack 44 into which a plurality of sample containers 42 containing a predetermined sample can be inserted, and a probe rack 46 containing a plurality of unused probes 10.
And a drain groove 48 are provided. Hereinafter, the operation of the dispensing device thus configured will be described.

First, a driving unit (not shown) operates,
Move the second guide 18 in the Y direction (probe rack 46 direction).
Move to When the tip 8 on which the probe 10 is not mounted is positioned above the probe rack 46, the driving unit operates to move the second support unit 16 in the X direction (the longitudinal direction of the probe rack 46). . When the lower edge of the tip 8 is aligned with the base end of the predetermined probe 10, the driving unit operates to move the first support unit 12 to the Z position.
Gently descend in the direction (direction approaching the probe 10).

When the tip 8 descends and the outer peripheral surface of the lower end of the tip 8 is fitted to the inner peripheral surface of the base end of the probe 10, the driving unit operates to activate the first support unit. 12 to Z
Then, the second guide 18 is moved in the Y direction (the direction approaching the drain groove 48). When the tip of the probe 10 is positioned above the drain groove 48, the pump 30 and the solenoid valve 32 operate. Then, the extruded water is pumped into the pressurized chamber of the syringe 6 through the filling tube 28. At the same time, the extruded water 7 is supplied to the probe 10 of the probe main body 2 through the connection tube 4. The extruded water 7 supplied to the probe 10 gushes from the tip of the probe 10 and falls into the drain groove 48. As a result,
Air bubbles in the connection tube 4 and the probe main body 2 are removed.

Thereafter, the syringe 6 is depressurized and a small amount of air is sucked into the tip of the probe 10 to form a first air layer 50 (see FIG. 2). Next, the drive section is operated to move the second guide section 18 in the Y direction (the direction approaching the container rack 44). When the distal end of the probe 10 is positioned above the container rack 44, the drive unit operates to move the second support 16 in the X direction (the longitudinal direction of the container rack 44). When the distal end of the probe 10 is aligned with a predetermined opening of the sample container 42, the drive unit operates to gently lower the first support unit 12 in the Z direction (a direction approaching the sample container 42). . As a result, probe 1
The leading end of No. 0 is inserted into the sample container 42 from the opening. The tip of the inserted probe 10 is
After gently contacting the surface of the sample 52 (see FIG. 2) housed in the sample 2, the tip of the probe 10 is further immersed in the sample 52 by a preset amount.

It is to be noted that whether or not the tip of the probe 10 has come into contact with the sample 52 is electrically detected, or the amount of the sample is measured in advance by using an optical method, ultrasonic waves, or the like. By applying a method or the like in which the probe 10 is stored, it is possible to prevent the probe 10 from being immersed in the sample 52 more than necessary. When the tip of the probe 10 is immersed in the sample 52 by a predetermined amount, the syringe 6 operates under reduced pressure to suck the sample 52 into the probe 10 (see FIG. 2).

The sample 52 sucked at this time has a function of preventing the extruded water 7 (see FIG. 2) from being mixed into the sample 52 to be discharged when the sample 52 to be described later is discharged. Therefore, hereinafter, the sample 52 to be discharged
This is referred to as an auxiliary sample 52 for the sake of clarifying the distinction from the above.

After a predetermined amount of the auxiliary sample 52 has been sucked into the probe 10, the drive unit operates to slowly raise the first support unit 12 in the Z direction (the direction away from the container rack 44). When the tip of the probe 10 is separated from the surface of the sample 52, the syringe 6 is depressurized and the probe 1
A little air is sucked into the tip of the second air layer 54.
(See FIG. 2). Thereafter, the first support portion 12 is gently lowered again in the Z direction (a direction approaching the sample 52 in the sample container 42). When the tip of the probe 10 is immersed in the sample 52 by a predetermined amount, the syringe 6 operates under reduced pressure to suck a predetermined amount of the sample 52 into the probe 10 (see FIG. 2).

The sample 52 aspirated at this time is the same sample as the auxiliary sample 52, but the sample 5 to be discharged into the reaction cell 34 at the time of discharging the sample 52 described later.
2.

After the sample 52 has been sucked, the drive section operates to raise the first support section 12 in the Z direction (in the direction away from the container rack 44). At the same time, the second guide 18
Is moved in the Y direction (a direction approaching the reaction vessel 36). When the distal end of the probe 10 is positioned at the upper part of the reaction container 36, the driving unit operates to cause the second support unit 16 to operate.
Is moved in the X direction (the longitudinal direction of the reaction vessel 36). When the distal end of the probe 10 is positioned above the predetermined reaction cell 34, the drive unit operates and the first support unit 1 is activated.
2 is lowered in the Z direction (a direction approaching the reaction cell 34). When the distance between the tip of the probe 10 and the inner surface of the reaction cell 34 becomes the optimum distance, the downward movement of the first support 12 is stopped. At this time, the syringe 6 is actuated under pressure to force the extruded water 7 toward the main body probe 2. This pumping force presses the first air layer 50 formed in the probe 10. With this pressing force, the first air layer 50 is compressed. The repulsive force against the compressive force acts on the auxiliary sample 52 and presses the auxiliary sample 52. The repulsive force against this pressing force is the second air layer 5.
Acts on 4. As a result, the second air layer 54 is compressed. The sample 52 sucked at the tip of the probe 10 is pressed toward the tip of the probe 10 by the repulsive force against the compression. With this pressing force, the sample 52 is discharged from the probe 10 and is accommodated in the reaction cell 34.

As described above, the pressurizing action of the syringe 6 is directly applied to the probe 1 via the incompressible extrusion water.
0 can be applied to the tip. Therefore, the delicate operation of the syringe 6 acts on the sample 52 sucked at the tip of the probe 10 with high accuracy. As a result, by controlling the pressurizing action of the syringe 6 so as to correspond to the amount of the sample 52 to be discharged into the reaction cell 34, the discharge amount of the sample 52 can be controlled with extremely high precision.

The provision of the first and second air layers 50 and 54 (see FIG. 2) in the probe 10 allows the extruded water 7 (see FIG. 2) to be ejected at the time of ejection. Can be prevented from being mixed in. That is, at the time of discharge, even if the extruded water 7 enters the auxiliary sample 52 through the gap between the first air layer 50 and the inner wall of the probe 10, the water is further removed below the auxiliary sample 52. Since the second air layer 54 is provided, the pushing water 7 is blocked by the second air layer 54. Therefore, the probe 10
The extruded water 7 is prevented from being mixed into the sample 52 to be discharged and sucked at the tip of the sample.

In the sample dispensing method of the present embodiment, the first and second air layers 50 and 54 function as double stoppers for the extruded water 7, and therefore include components having a surface active effect such as proteins. Even when the sample 52 to be discharged is discharged, the extruded water 7 is supplied to the first and second air layers 5.
The sample does not enter the sample 52 sucked to the tip of the probe 10 by passing over the points 0 and 54. As a result, even if the sample 52 of any property is dispensed, it can be performed with high accuracy.

After the discharge of the sample 52 is completed,
The drive unit operates to raise the first support unit 12 in the Z direction (the direction away from the reaction vessel 36). And the second
Guide 18 in the Y direction (direction approaching the detachable member 38)
Move to When the probe main body 2 is positioned above the detachable member 38, the driving unit operates to move the second support part 16 in the X direction (the probe 10
6), and at the same time, the first support 12 is moved in the Z direction (the direction approaching the recess 56). When the chip 8 is engaged with the concave portion 56, the first support portion 12 is gently lifted in the Z direction (the direction away from the concave portion 56). As a result, the probe 10 is detached from the tip 8 while engaging with the recess 56. The detached probe 10 falls into the accommodation section 40 arranged below the detachable member 38.

As described above, by disposing of the used probe 10 in a disposable manner, prevention of infection by the infectious sample 52 is achieved. Note that it is also preferable that a chemical having a bactericidal effect is stored in the storage section 40 in advance. As a result, airborne infection can be prevented by the chemicals. Further, the probe 10 can be reused. The tip 8 from which the probe 10 has been detached is set at an initial position for sucking and discharging the next sample 52.

The sample dispensing method of the present invention is not limited to the configuration of the above-described embodiment. For example, a removal step of removing the sample 52 attached to the outer wall of the probe 10 after sucking the sample 52 may be added. This removal step improves the dispensing accuracy of the sample 52. Further, it may be configured such that only the second air layer 54 is provided in the probe 10. In this case, even if the extruded water gets over the second air layer 54 and mixes into the sample 52 at the time of ejection, a relatively large amount of the extruded water does not affect the amount of the sample 52 to be ejected. It is desirable that the sample 52 be sucked.

[0030]

As is clear from the above description,
According to the dispensing method according to the present invention, the detachable probe
Liquid for analysis composed in order from the probe and probe tip,
2 air layer, auxiliary liquid, 1st air layer, and non-pressure
Analytical liquid is used for analysis due to short and low cost operation.
Prevention of body contamination and high-precision dispensing
It is possible to do.

[Brief description of the drawings]

FIG. 1 is a perspective view schematically showing an entire dispensing apparatus to which a dispensing method according to one embodiment of the present invention is applied.

FIG. 2 is an enlarged sectional view showing a part of a probe main body provided in the dispensing apparatus of FIG. 1;

[Explanation of symbols]

2: Probe body, 6: Syringe, 7: Extruded water, 8
... Chip, 10 ... Probe, 34 ... Reaction cell, 36 ... Reaction vessel, 38 ... Removal member, 50 ... First air layer, 52 ...
Sample, 54 ... second air layer.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-1-50927 (JP, A) JP-A-3-9263 (JP, A) JP-A-58-129366 (JP, A) JP-A-1- 284761 (JP, A) JP-A 2-140472 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G01N 35/00-35/10 G01N 1/00 101

Claims (1)

(57) [Claims] 1. A dispensing method for dispensing a plurality of types of analysis liquids : a step of attaching a detachable probe to a tip of a probe main body ; and a step of filling an incompressible liquid in the attached probe. Introducing a first air layer by sucking some air into the probe after introducing the incompressible liquid ;
And then aspirate the supplementary liquid, and
Air to form a second air layer, and then the solution for analysis.
The body is aspirated and the liquid for analysis and the second
Air layer, auxiliary liquid, first air layer, and uncompressed
Step and which constitute the sexual liquid; discharge step and quantitatively discharge the aspirated liquid for analysis; dispensing method characterized by having: a step of leaving the probe from the distal end of the probe body after the discharge process.