JPS6142210B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for diluting a sample such as blood to a high magnification.

Conventionally, blood samples used for blood cell counting, etc. are obtained by diluting blood several hundred times to tens of thousands of times using physiological saline, etc., to obtain a dilution concentration suitable for counting blood cells one by one optically or electrically. Counting is performed using The dilution device used for these dilutions is one that aspirates a predetermined amount of a sample such as blood with a suction pipette, and then discharges it together with the diluent to dilute it to a predetermined magnification. In more detail, based on FIG. 1 showing an example, this device includes a suction pipette 1, a micro-quantity syringe 2, a piston 3, a diluted liquid metering syringe 4, a piston 5, valves 6 and 7, and a communication tube 8. , 9, 10, a diluent tank 11, etc., a micro metering syringe 2, a diluent metering syringe 4, and a communication tube 8, 9, 1.
0. The inside of the suction pipette 1 is filled with a diluent in advance because if air gets mixed in, a quantitative error will occur.

To perform dilution using such a diluter, first, a sample 13 such as blood from a sample container 12 is aspirated into the suction pipette 1. That is, when the sample is aspirated, the diluent already filled in the communication tube 8 is drawn into the piston 3.
This is done by moving it into the micro-metering syringe 2 by lowering the syringe. Note that since the sample is in a very small amount, it does not move to the inside of the small amount metering syringe 2.

On the other hand, a predetermined amount of the diluent 14 in the diluent tank 11 is transferred to the diluent metering syringe 4 by opening the valve 7 and lowering the piston 5.

After that, the valve 7 is closed, the valve 6 is opened, and the pistons 3 and 5 are raised to a predetermined position. A dilution operation is then performed.

Normal dilution metering syringes measure about 10ml, while micrometering syringes measure 0.1 to 0.02ml.
This yields a dilution factor of 100 to 500 times. Dilution tens of thousands of times is achieved by repeating the above operation twice.

The pistons 3 and 5 are driven by a combination of a motor and a cam, or by a cylinder using hydraulic pressure, air pressure, or the like.

The dilution method using the above diluter is compared with a method in which the sample is aspirated directly into the pipette using a micropipette or the like, and the sample is discharged into a pre-quantified dilution solution. It has the advantage of not requiring any skill, which reduces individual differences among operators, and eliminates the problem of contamination since the inside of the pipette is drained while being washed with new diluted solution. If air bubbles get mixed inside, it tends to cause quantitative errors, and it has the disadvantage of having to worry about piping leaks, etc.

In particular, instead of directly quantifying a sample such as blood as in this example, the sample is indirectly quantitatively determined by the stroke of the piston 3 via the diluent filling the inside of the communication tube 8 and the inside of the micro-metering syringe 2. This method is sensitive to the condition of the diluent at the tip of the suction pipette 1, breathing in the communication tube 8, leakage due to deterioration of the valve 6, etc., and also depends on how to wipe off the sample that has adhered to the outside of the suction pipette 1. However, there was a drawback in that it seriously affected the measurement results of the sample after dilution. In particular, the shape of the diluted solution at the tip of the suction pipette before quantification not only causes a quantification error, but also has the risk of the diluted solution getting mixed into the sample container 12.
In addition, dilution errors tend to occur depending on how the sample is wiped off after aspirating it, so methods such as reducing the inner diameter of the suction pipette have been taken to reduce these effects, but the flow rate is small and dilution errors are likely to occur. Another drawback occurred that the time required was too large.

The present invention solves the above-mentioned drawbacks and provides a highly accurate dilution device.The present invention will be explained in more detail below based on embodiments shown in the drawings.

The apparatus of the present invention is broadly divided into two parts: a sample quantification mechanism 16 and a diluent quantification mechanism 17, and the latter diluent quantification mechanism 17 has almost the same configuration as the dilution quantification mechanism of a conventional diluter. On the other hand, the former sample metering mechanism 16 includes a suction pipe 18 made of a material such as glass having a uniform inner diameter, and a piston 1 made of a material such as fluorine-based resin that has excellent friction resistance and chemical resistance.
9, a relay pipe 20, and a main body 21. Since the main part of the sample quantification mechanism 16 is shaped to protrude to the outside of the apparatus, fluid communication with the inside is performed via the joint 22. Also,
For quantitative determination of the diluted solution, there is an inlet 23 and an outlet 2 on the head.
This is carried out by a diluent metering syringe 4 and a piston 5.

Furthermore, the suction pipe 18 is inserted into the interior of the relay pipe 20, and is fixed with a fixing screw 26 having a threaded thread whose inner diameter is inclined and whose inner diameter becomes smaller as it goes deeper.

The piston 5 and the piston 19 are driven by a motor and a cam, or an air cylinder using an air pressure source, or the like.

In order to carry out a dilution operation using the apparatus configured as described above, first, as shown in FIG. 3, the tip of the piston 19 is adjusted so as to protrude somewhat from the end surface of the suction pipe 18 and then stop. When a sample such as blood is aspirated in this state, a predetermined amount of the sample 13 is suctioned in direct contact with the tip of the piston 19, as shown in FIG. Stop at.

On the other hand, in FIG. 2, a predetermined amount of the diluent is sucked into the diluent metering syringe 4 from the inlet 23 through the valve 7 as the piston 5 descends.

Next, as shown in FIG. 5, the piston 19 is further raised so that the tip of the piston 19 is located in the internal space 25 of the relay pipe 20, the valve 6 in FIG. 2 is opened, and the piston 5 is raised. The diluted solution is sent into the relay pipe 20 from the discharge port 24 via the valve 6 and the joint 22, and is discharged to the outside from the suction pipe 18 together with the sample 13 that has been aspirated. When the piston 5 rises to a predetermined position and stops, the piston 19, which is in the state shown in FIG. 5, descends and stops at a position where the tip of the piston 19 protrudes from the end surface of the suction pipe 18, as shown in FIG.

Dilution is performed as described above, but according to the apparatus of the present invention, the tip of the piston 19 directly touches the sample 13.
Errors are less likely to occur because the sample is aspirated without intervening air or other liquids, and the end surface of the piston that comes into contact with the sample is constantly cleaned with the diluent when it is discharged. There is no problem of contamination.Also, even if the sample adheres around the suction pipe, the end face of the quantified sample can be temporarily sucked into the suction pipe, making it difficult to cause errors due to wiping. There are other effects.

Further, the suction pipe 18 is inserted into the relay pipe 20, and a fixing screw 26 with a tapered inner diameter is inserted into the relay pipe 20.
Therefore, if fine adjustment is required, loosen the fixing screw 26 and make the adjustment so that the distance from the end surface of the piston 19 to the open end of the suction pipe 18 in the state shown in Fig. 4 is the specified length. In addition, the suction pipe 18 is easy to replace, and even if it becomes damaged or dirty, it can be easily replaced, and the suction pipe itself can be supplied at a low cost, making it a disposable part. It has many advantages, such as being able to be used as

Furthermore, the mechanism for quantifying the diluted liquid is not limited to the combination of the piston 5 and the syringe 4 as shown in this embodiment, but can also be achieved by other quantitative methods, for example, as shown in FIG. The diluted solution is sucked into the metering container 26 having a predetermined volume by a pneumatic source of pressure and positive pressure, and then positive pressure is applied to the metering container 2.
6 to the relay pipe 20, etc. When the valves 7, 27, and 28 are opened and negative pressure is applied to the metering container 26, the diluent 14 is sucked, and the liquid level of the diluent 14 is detected by a position detection device consisting of a light source 29, a light receiving device 30, etc. When reaches the valve 7,
27 is closed, after which the valve 28 switches the negative pressure to positive pressure, and when the valves 27 and 6 are opened, the relay pipe 20
The diluent is transferred to and dilution is performed.

Even if the method for quantifying the diluted liquid as described above is used, the sample quantity is accurate, so the dilution accuracy will not deteriorate.In fact, if an air cylinder or the like is used to drive the sample quantity measurement mechanism 16, etc. Using the quantitative method described above is more effective because the driving sources can be unified, and the size can be reduced.

If you use this device to dilute a sample such as blood, there will be no air or other liquid involved when drawing the sample.
Since quantification is performed by directly contacting the sample with the piston, highly accurate dilution can be performed without limiting the method of quantifying the diluted solution, and this can be used for preparing samples for blood cell counting and other dilutions that require high precision. If used, it is very effective and does not introduce errors in the measurement results.

[Brief explanation of the drawing]

FIG. 1 is an example of a dilution device using a conventional method, FIG. 2 is a configuration diagram of an embodiment of the present invention, and FIGS. 3, 4, and 5 are explanatory diagrams of the operation of the device of the present invention. FIG. 6 is an explanatory diagram of another embodiment. 12... Sample container, 13... Sample, 15... Beaker, 18... Suction pipe, 5, 19... Piston, 20... Relay pipe, 21... Main body, 22... Joint, 6, 7, 27 ,28... valve.

Claims (1)

[Claims] 1 Equipped with a sample quantification mechanism that aspirates and quantifies a predetermined amount of a liquid sample, and a diluent quantification mechanism that aspirates and quantifies a predetermined amount of a diluent, and the diluent that has been aspirated in a fixed amount is simultaneously discharged together with the quantified sample. In a dilution device that performs a dilution operation at a predetermined magnification, the sample quantification mechanism includes a suction pipe having a uniform inner diameter, a piston that fits into the suction pipe and is movable through the inside of the suction pipe, and the suction pipe. a relay tube that is inserted into and held in the upper part of the outer wall of the piston and has a space with an inner diameter slightly larger than the outer diameter of the piston and into which a diluent can be introduced; The tip of the piston protrudes outside the lower end surface of the suction pipe and stops before suctioning the sample, and when aspirating the sample, the sample is drawn in close contact with the tip of the piston, and after quantification. The tip of the piston is temporarily stopped below the upper end surface of the suction pipe, and when the diluent metered by the diluent metering mechanism is transferred to the relay pipe, the tip of the piston is temporarily stopped below the upper end surface of the suction pipe. The diluting device is located inside the relay tube, and the diluent is discharged from the space inside the relay tube through the suction pipe to the outside together with the quantified sample, thereby diluting the sample to a predetermined ratio.