JPS61124845A - Dispensing device - Google Patents

Abstract

PURPOSE:To distribute a minute amount of a liquid specimen with good accu racy, by providing a distribution nozzle equipped with a space part having a wider cross-sectional area to the upper part of a sucking/emitting pipe utiliz ing a capillary rising phenomenon. CONSTITUTION:A distribution nozzle 1 consists of a sucking/emitting pipe 1a and a space part 1b having a cross-sectional area larger than that of said pipe 1a and constituted at the leading end of a communication pipe 2 in a freely detachable manner. At the sucking time of a specimen, a plunger 6 is raised and a communication port 3 is opened to make the pressure of a pressure control chamber 5 equal to external pressure and, subsequently, the sucking/emitting pipe 1a is immersed in a specimen solution for a definite time before moved to a specimen emitting place. Next, the plunger 6 is fallen to close the communication port 3 and a box body 4 is further compressed to raise the pressure of the chamber 5 to emit the specimen. After the completion of distribution operation, the distribution nozzle 1 is detached from the communication pipe 2 and replacement with a new nozzle to prepare for the next process.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a dispensing nozzle suitable for handling a minute amount of liquid sample and a dispensing device using the same.

[Background of the Invention J] As shown in Japanese Patent Application Laid-Open No. 58-208666, a conventional dispensing device has a reagent liquid feeding device and a dispensing nozzle connected to each other, and the centrifuge tube is tilted so that the tip of the nozzle is connected to the injection container. Dispensing in units of micrometers was possible by contacting the sample. However, in order to further miniaturize the amount of sample to be handled without reducing the size of one dispensing tank, the above method has a limit due to errors caused by a difference in the timing of stopping the drive of the pump.

Furthermore, in a dispensing device using a pump, the pump suction path must be filled with sample liquid, which poses a problem in that dispensing operations become difficult when the amount of sample to be supplied is small.

[Purpose of the invention]

An object of the present invention is to provide a dispensing device suitable for dispensing a very small amount of liquid of 1 μΩ or less.

(Summary of the invention) ' The present invention is a liquid dispensing device that utilizes the phenomenon of capillary rise. The suction and discharge pipe radius is r, the liquid surface tension is σ, the contact angle between the liquid and the pipe is θ, and the maximum liquid height is When L is the density, ρ is the gravitational acceleration, and g is the gravitational acceleration, the following equation holds true.

r ρ g At this time, if the suction and discharge pipe length is set to Q (A<L) and a space with a sufficiently large cross-sectional area is provided above it, the liquid rise can be stopped at a height consideration.The present invention utilizes the above phenomenon. The aim is to quantify the amount dispensed.

(Embodiments of the invention) A configuration diagram of a first embodiment of the present invention is shown in FIG.

This embodiment consists of a suction and discharge pipe 1a and a space 1b having a cross-sectional area larger than the cross-sectional area of the suction and discharge pipe, and includes a dispensing nozzle 1, a communication hole 3, and an elastic member 4a that are configured to be detachably attached to the tip of a communication pipe 2. A pressure adjustment chamber 5 surrounded by a box body 4, a plunger 6 that opens and closes the communication hole 3, springs 7a and 7b that determine the equilibrium position of the plunger 6, a solenoid 8, and an outside air communication hole 9a.

The operation of this embodiment, which is composed of the outer box 101 having the outer box 9b and the position control mechanism 11 for positioning the dispensing nozzle 1, is as follows. When sucking a sample, the plunger 6 is raised to open the communication hole 3 and the pressure in the pressure adjustment chamber 5 is made equal to the external pressure.Next, the suction and discharge pipe 1a is immersed in the suction sample liquid and this state is maintained for a certain period of time. , take the suction and discharge tube out of the sample liquid and move it to the sample discharge location. At this time, the communication hole 3 is kept open in order to prevent the balance between the external pressure and the pressure in the pressure adjustment chamber 5 from being lost and the inhaled sample being discharged during movement. On the other hand, when discharging a sample, after positioning the suction and discharge pipe 1a in the discharge container, the plunger 6 is lowered to close the communication hole 3, and the box body 4 is compressed to increase the pressure in the pressure adjustment chamber 5, thereby discharging the sample. It is discharged from the suction and discharge pipe 1a.

Finally, after the above dispensing operation is completed, the dispensing nozzle 1, which is configured to be detachable, is connected to the communicating tube 2 using a handling mechanism, etc.
Remove the nozzle, replace it with a dispensing nozzle that is not contaminated with the sample reagent, and prepare for the next process.0 This example is suitable for dispensing samples such as enzymes, which are expensive and have a small amount of sample to be supplied and are highly susceptible to contamination. . As for the shape of the dispensing nozzle 1, it is also conceivable to make the suction and discharge pipe 1a protrude into the space 1b as shown in FIG. At this time, even if the pressure in the pressure adjustment chamber 5 before suction of the sample is slightly lower than the external pressure and the amount of sample sucked exceeds the amount determined by the dimensions of the suction and discharge pipe 1a.

There is an advantage that the discharged sample amount does not exceed a set value.

Next, a partial view of the second embodiment is shown in FIG. 3. This embodiment is suitable for dispensing operations that do not require replacing the dispensing nozzle 1, and the suction and discharge pipes 1a in the first embodiment are connected. It is provided at the position of tube 2. In order to improve the dispensing accuracy, it is also possible to make the suction and discharge pipe 1a of the dispensing nozzle 1 protrude into the space 5 in the same way as shown in FIG.
figure).

Furthermore, a third embodiment is shown in FIG.
The pressure is adjusted by switching between the pressure adjustment chamber 5 and the air compressor 12 or between the pressure adjustment chamber 5 and the atmosphere communication hole 14. Further, in this embodiment, the sample container 15 is equipped with a position control mechanism 11. The operation of this embodiment is the same as that described in the first embodiment except for the pressure adjustment method and position control mechanism.

Note that if a droplet remains in the dispensing nozzle 1 before the sample is inhaled, the gas pressure between the droplet and the suction liquid increases, which prevents the sample liquid from rising. Therefore.

If there is a possibility that droplets remain in the dispensing nozzle 1 before inhalation, the pressure in the pressure adjustment chamber 5 is increased once to blow the droplets away, and the pressure in the pressure adjustment chamber 5 is adjusted to the external pressure. It is advisable to perform the above-mentioned dispensing operation after they become equal.

(Effects of the Invention) As shown above, according to the present invention, a minute amount of liquid can be dispensed with high precision.

[Brief explanation of the drawing]

Fig. 1 is a configuration diagram of the first embodiment, Fig. 2 is a diagram showing another example of the dispensing nozzle, Fig. 3 is a partial diagram of the second embodiment, and Fig. 4 is a partial diagram of the second embodiment. Note: An example in which the nozzle shape is changed, FIG. 5 is a system diagram of the third embodiment. 1...Dispensing nozzle, 3...Atmospheric communication hole, 5...Pressure adjustment￥J 1 Figure 3 Figure 4 Figure 5 Figure 5

Claims (1)

[Claims] 1. In a dispensing device consisting of a dispensing nozzle, a pressure adjustment means for adjusting the internal pressure of the dispensing nozzle, and a position control means for controlling the relative position of the dispensing nozzle and a container for collecting a chemical solution, as a dispensing nozzle, A dispensing device comprising: a suction/discharge pipe that utilizes a capillary rise phenomenon, and a dispensing nozzle provided above the suction/discharge pipe with a space having a cross-sectional area larger than the cross-sectional area of the suction/discharge pipe.