JP3029718B2 - Automatic chemical analyzer sampling system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sampling system for an automatic chemical analyzer capable of detecting a liquid level without bringing a pipette probe into contact with a liquid surface to be detected and dispensing a sample.

[0002]

2. Description of the Related Art An automatic chemical analyzer will be described with reference to FIG.

[0003] This apparatus has a disk-shaped sampler 3.
After a sample pump or reagent solution is pumped into the dedicated pipette probes 34 and 35 from the sample or reagent containers 32 and 33 erected on 0 and 31 by a sampling pump to perform a constant amount suction, these solutions are discharged into the reaction container 36. , Stirrer 38
Is a device for performing chemical analysis by measuring and mixing the reaction process with the photometric unit 37. Further, the pipette probe nozzle 34a, which is contaminated by a
A probe washing unit 39 and a reaction container washing unit 40 are provided for washing the reactor and the reaction container 36.

Next, a method of sampling a small amount of a sample using a sampling system of a conventional automatic chemical analyzer will be described.

First, a reagent solution contained in a reagent container 33 is supplied to a reaction container 36 via a pipette probe 35 dedicated to the reagent.
Dispense into Next, the sample solution is sucked into the pipette probe 34 dedicated to the sample, the outer wall thereof is washed by the probe washing unit 39, and then moved onto the reaction vessel 36, so that the probe nozzle 3
4a is lowered. At this time, when the tip of the pipette probe nozzle 34a comes into contact with the liquid surface of the reagent liquid, the liquid level detection sensor integrated with the pipette probe nozzle 34a detects the liquid surface contact and brings the nozzle tip into contact with the liquid surface. In this state, the lowering of the probe nozzle 34a is stopped. As described above, when the lowering of the probe nozzle 34a stops, the sample liquid inside the pipette probe 34 is discharged to the reaction vessel 36.

Then, in order to dispense the next sample solution, FIG.
The pipette probe nozzle 34a is moved to the probe cleaning section 39 as shown in FIG.
a, the cleaning liquid 41 is discharged from the inside of the pipette probe nozzle 34a, and the probe cleaning unit 3
From 9, the cleaning liquid 42 is jetted in a fixed amount to clean the inner and outer walls of the pipette probe nozzle 34 a.

[0007]

However, in the sampling system of the above-mentioned automatic chemical analyzer, when a sample solution or the like is discharged to a reagent solution or the like, it is necessary to confirm that the tip of the pipette probe nozzle has come into contact with the liquid surface before the pipette probe. In order to stop the lowering operation of the nozzle, the pipette probe nozzle is brought into contact with the reagent liquid or the like during both the suction and the discharge of the sample liquid or the like. Therefore, the outer wall of the pipette probe nozzle is contaminated with a reagent solution or the like, which causes a problem that the contaminated outer wall must be sufficiently cleaned not only after aspirating the sample but also after discharging the sample.

In particular, high sensitivity items such as immunity items (concentration 1
0 ^-9 g / ml or less, when measuring the concentration range 0-10 ^6), contamination caused by bringing the other solutions between vessels at the time of sampling, i.e., carryover occurs. In order to completely prevent the occurrence of carry-over, it is necessary to increase the washing time of the pipette probe, which causes a decrease in the sample processing speed of the automatic chemical analyzer.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and does not allow the pipette probe nozzle to come into contact with the solution in the reaction vessel when the sample is discharged onto the surface of the reagent or the like. It is an object of the present invention to provide a sampling system for an automatic chemical analyzer that can improve the efficiency of probe cleaning and the like.

[0010]

SUMMARY OF THE INVENTION A sampling system for an automatic chemical analyzer according to the present invention is characterized in that a solution of a sample or a reagent is quantitatively aspirated from a container mounted on a disk-shaped sampler by operating a sampling pump into a pipette probe. In a sampling system of an automatic chemical analyzer for measuring the reaction process by discharging and mixing these solutions into a reaction vessel, a probe control means for controlling the vertical movement of a pipette probe nozzle and a pipette probe by operating a sampling pump Pump control means for aspirating the sample into the reaction vessel and discharging the aspirated sample into the reaction vessel, and finely moving the sampling pump to discharge the solution such as a sample drawn into the pipette probe to the reaction vessel. Form a droplet of suction liquid at the tip of the nozzle Characterized in that a droplet formation signal generating means for outputting a control signal because the pump control means.

[0011]

According to the sampling system of the automatic chemical analyzer of the above means, since the droplet of the sample such as a suction solution is formed in a hemispherical shape at the tip of the pipette probe nozzle, only the droplet formed at the tip of the nozzle is used as a reagent. The sample can be dispensed without bringing the tip of the pipette probe nozzle into direct contact with the liquid surface such as a reagent solution, although the sample is brought into contact with the liquid surface such as a liquid.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a sampling system for an automatic chemical analyzer according to the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an apparatus to which this embodiment is applied.

This apparatus is equipped with a liquid level detecting sensor for detecting liquid level contact at the tip of the nozzle, and is capable of sucking and discharging a sample through a pipette probe nozzle 1a. A stepping motor 2 constituting a driving device for moving the probe nozzle 1a up and down, a sampling pump 3 operating for sucking a sample through the pipette probe nozzle 1a, and a driving device for operating the sampling pump 3 A stepping motor 4, a probe cleaning unit 5 for cleaning the outer wall of the pipette probe nozzle 1a, an outer wall cleaning pump 6 for sending a cleaning liquid to the probe cleaning unit 5, and an inner wall of the pipette probe nozzle 1a via the sampling pump 3. The cleaning liquid is discharged and the cleaning liquid line 7
Cleaning pump 8 for sucking the cleaning liquid from the inside, the cleaning pump 8 and the cleaning liquid line 7 or the pipette probe nozzle 1
a, and a stepping motor 2, 4 or an inner wall cleaning pump 8 based on a predetermined program or an output signal from a liquid level detection sensor of the pipette probe nozzle 1a. And a control unit 10 that outputs a command signal for performing these controls to the outer wall cleaning pump 6 and the solenoid valve 9.

FIG. 2 is a functional block diagram showing a basic configuration of the control unit 10, the pipette probe 1, and the sampling pump 3 of the apparatus.

The control unit 10 includes a probe control means 11 for outputting a command signal for controlling the vertical movement of the pipette probe nozzle 1a to the step motor 2 based on a predetermined program, an input signal, and the like; A pump which operates the sampling pump 4 based on an input signal or the like to suck a sample into the pipette probe nozzle 1a and outputs a command signal to the step motor 4 for controlling discharge of the sucked sample into the reaction vessel 20. Based on the control means 12 and a predetermined program at the time of discharging the sample, a control signal for finely moving the sampling pump 3 to form a droplet of the suction liquid at the tip of the pipette probe nozzle 1a is output to the pump control means 12. Droplet formation signal generating means 13 and pipette probe nozzle 1
a liquid level recognizing means 15 for recognizing the liquid level contact of the probe nozzle 1a based on the detection signal output from the liquid level detecting sensor a and outputting a contact signal to the stop signal generating means 14;
Stop signal generating means 14 for outputting to the probe control means 11 a stop signal for stopping the lowering operation of the probe nozzle 1a without bringing the tip of the pipette probe nozzle 1a into contact with a liquid surface such as a reagent based on the contact signal; Although not shown in the figure, the control unit includes various control means for controlling the operation of the inner wall cleaning pump, the outer wall cleaning pump, the solenoid valve, and the like based on a program or the like.

The operation of the system when dispensing a sample onto the surface of the reagent solution 21 dispensed into the reaction vessel 20 using the above-described apparatus will be described.

The control unit 10 first outputs a command signal to the step motor 2 based on a predetermined program to move the pipette probe nozzle 1a onto the sample container.
Move down into the sample container. At this time, when the liquid level detection sensor at the tip of the probe nozzle 1a detects the liquid level contact, the control unit 10 outputs a command signal to the step motor 2 to stop the lowering operation of the pipette probe 1a. Then, a command signal is sent to the step motor 4 with the electromagnetic valve 9 closed, and the sampling pump 3 is operated to aspirate a fixed amount of the sample liquid into the pipette probe nozzle 1a.
The pipette probe nozzle 1a is raised and moved above the reaction vessel 20.

The pipette probe nozzle 1a is connected to the reaction vessel 2
When the movement is stopped above 0, a control signal is output from the droplet formation signal generation means 13 of the control unit 10 to the pump control means 12. Then, based on the control signal, the pump control means 1
From 2, a command signal for slightly operating the sampling pump 3 is output to the step motor 4. As a result, the sampling pump 3 is slightly operated, and the sample liquid droplet 22 is formed in a hemispherical shape at the tip of the pipette probe nozzle 1a.

Next, a command signal for lowering the pipette probe nozzle 1a is output from the probe control means 11 of the controller 10 to the step motor 2, and the pipette probe nozzle 1a performs the lowering operation while holding the droplet 22 at the tip of the nozzle. (FIG. 3-A). And the droplet 2 at the tip of the nozzle
When the lower end of 2 comes in contact with the liquid surface of the reagent liquid 21 in the reaction container 20, a detection signal is output from the liquid level detection sensor provided at the nozzle tip to the liquid level recognition means 15 (FIG. 3-B).

The liquid level recognizing means 15 outputs a contact signal to the stop signal generating means 14 upon confirming the contact between the liquid drop 22 formed at the tip of the nozzle 1a and the liquid level to be detected. Based on this contact signal, the stop signal generating means 14 outputs a stop signal to stop control of the lowering of the probe nozzle 1a to the probe control means 11. Then, a command signal for stopping the lowering operation of the pipette probe nozzle 1a is output from the probe control means 11 to the step motor 2, and the lowering operation of the pipette probe nozzle 1a stops in a state where only the droplet at the nozzle tip is in liquid contact. . That is, the lowering operation of the pipette probe nozzle 1a can be stopped without bringing the tip of the pipette probe nozzle 1a into direct contact with the surface of the reagent solution.

Next, a command signal for controlling the discharge of the sample liquid is output from the pump control means 12 to the step motor 4,
The sampling motor 3 is operated to discharge a fixed amount of the reagent solution from the pipette probe nozzle 1a (FIG. 3-C).

After the discharge of the sample liquid by the above operation, the inner and outer walls of the pipette probe nozzle 1a contaminated with the sample liquid are washed before the next sample dispensing.

This cleaning operation is performed as follows. First, the pipette probe nozzle 1a is moved to the probe cleaning unit 5, and the inner and outer wall cleaning pumps 8 and 6 suck the cleaning liquid from the cleaning liquid line 7 while maintaining the electromagnetic valve 9 in an open state between bc. . Then, the electromagnetic valve 9 is switched to the open state, and the inner and outer wall cleaning pumps 8 and 6 are operated to spray the cleaning liquid onto the inner and outer walls of the pipette probe nozzle 1a to perform cleaning.

Next, an experimental example and an experimental result comparing the degree of contamination of the outer wall of the pipette probe nozzle 1a when the present invention and the conventional method are used will be described.

After the buffer solution is sucked into the pipette probe, the solution is discharged into a reaction vessel in which 1.07 U / ml enzyme solution (peroxidase) has been previously dispensed using another pipette probe. Then, the cleaning liquid was sprayed only on the inner wall of the pipette probe to sufficiently clean the pipette probe. Next, after rinsing the outer wall of the probe nozzle in another reaction vessel into which a reagent for measuring the enzyme activity has been dispensed and causing a chemical reaction, the immersion distance of the probel and the outer wall are measured by measuring the enzyme activity. An experiment was performed to obtain a relationship between the degree of contamination. The degree of outer wall contamination as used herein means the residual enzyme rate, that is, the enzyme activity value (unit: U / ml) in the solution in which the outer wall of the probe nozzle has been rinsed, is calculated from the activity value of the enzyme stock solution (U /
ml) and expressed as a percentage.

The method of discharging the buffer solution includes (1)
When a droplet is formed at the tip of the nozzle by applying the present invention and the sample is discharged without bringing the tip of the nozzle into contact with the liquid surface in the reaction vessel, (2) the tip of the nozzle is applied to the liquid surface by applying the conventional method. (3) The case where the sample was ejected while the tip of the nozzle was immersed in the liquid surface was performed.

As a result of this experiment, a curve diagram showing the relationship between the probel immersion distance and the residual ratio of enzyme activity shown in FIG. 4 was obtained. As shown in this curve diagram, it was demonstrated that the use of the sampling system of the automatic chemical analyzer according to the present invention can significantly reduce the contamination of the outer wall of the pipette probe nozzle as compared with the conventional method.

[0029]

According to the sampling system of the automatic chemical analyzer of the present invention, since the sample liquid or the like is discharged by forming a droplet at the tip of the pipette probe, the sample is discharged by contacting the pipette probe nozzle with the liquid surface. Wall contamination can be eliminated. Therefore, when measuring general biochemical items, the pipette probe can be washed more quickly, and as a result, the speed of the chemical analysis process is improved. Also, in the probe washing performed for the immunity items, carryover can be achieved without requiring a sufficiently long washing time as in the conventional case. Therefore, it is possible to measure highly sensitive test items such as immune items without reducing the speed of the chemical analysis process.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an apparatus to which an embodiment of the present invention is applied.

FIG. 2 is a functional block diagram illustrating a basic configuration of a control unit of the apparatus.

FIG. 3 is an explanatory diagram showing an operation of the sampling system according to one embodiment of the present invention.

FIG. 4 is a curve diagram showing a relationship between a probe immersion distance and a residual ratio of enzyme activity.

FIG. 5 is a schematic view showing a general automatic chemical analyzer to which the present invention is applied.

FIG. 6 is a sectional view showing cleaning of a pipette probe nozzle in the same apparatus.

[Explanation of symbols]

 Reference Signs List 1 pipette probe 1a pipette probe nozzle 2, 4 step motor 3 sampling pump 10 control unit 20 reaction vessel 22 droplet

Claims (1)

(57) [Claims] 1. A sampling pump is operated into a pipette probe to aspirate a fixed amount of a sample or reagent solution from a container provided on a disk-shaped sampler, and the solution is discharged and mixed into a reaction container to measure a reaction process. In a sampling system of an automatic chemical analyzer, a probe control means for controlling vertical movement of a pipette probe nozzle, a sampling pump is operated to aspirate a sample into a pipette probe, and the aspirated sample is placed in a reaction vessel. A pump control means for discharging and a control signal for forming a droplet of the suction liquid at the tip of the pipette probe nozzle by slightly moving the sampling pump when discharging a solution such as a sample sucked into the pipette probe to the reaction container. A droplet formation signal generating means for outputting to the pump control means. Sampling system of the automatic chemical analyzer according to claim and.