JPH02259449A - sample inspection equipment - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a sample testing device such as a flow cytometer.

[Prior Art] Conventionally, sample supply methods mainly used in sample testing devices such as flow cytometers and particle counters include:
A method is known in which a sample tube is inserted into a sample liquid container containing the sample liquid to be measured, the container is sealed and fixed, and the inside of the container is pressurized to push a specified amount of sample liquid into the sample tube and supply it to the test area. It will be done.

However, in the conventional sample testing device described above, if the sample liquid prepared in the sample liquid container is less than a predetermined amount, all the sample liquid is sent and the sample liquid container becomes empty. After that, the pressurization operation continued, and air was forced into the sample tube.

Therefore, the applicant first attached a gas detection sensor to the sample tube near the sample liquid container, detected the air sent into the sample tube, and when air was detected, stopped the sample liquid feeding operation and started measurement. We proposed a sample testing device with a mechanism to eliminate the negative effects of

[Problem to be Solved by the Invention] However, in this case, if the sample liquid feeding operation is stopped at the same time as the air in the tube is detected, the sample liquid remaining in the sample tube at the time of stopping will be wasted. It ends up. To prevent this, if the sensor detects air, the liquid feeding operation is continued for a certain period of time, and the operation is stopped after the sample liquid in the sample tube is sent to the flow cell, so that the sample liquid is not wasted. Alternatively, if the sensor is installed in the middle of the sample tube near the flow cell, the sample liquid will not be wasted.

However, when air is present in the sample tube, the internal resistance inside the tube changes and the pressure of the sample liquid in the flow cell changes, causing the flow diameter of the sample liquid flowing through the flow cell flow section, that is, the sample flow diameter to fluctuate. There was a problem with it.

When the sample flow diameter changes, the coefficient of variation (CV value) and the like change, deteriorating measurement accuracy.

[Purpose of the invention] The present invention provides a solution that can be used even if the sample runs out and air is pumped into the sample tube during sample supply.
To provide a sample testing device capable of sending the sample remaining in a sample tube to a testing part while keeping the sample flow diameter at the testing part constant, eliminating waste of sample liquid, and capable of highly accurate measurement. With the goal.

[Means for Achieving the Object] The present invention achieves the above-mentioned object by immersing the end of a sample tube in a sample liquid container containing a sample liquid, sealing the sample liquid, and pressurizing the inside of the sample liquid container. In a sample testing device that supplies a sample liquid to the sample tube and tests the sample in the test section, a detection means is provided in the middle of the sample tube and detects gas in the sample tube. and a sample testing device characterized by having a control means for changing the pressurization value in the sample liquid container so that the sample flow diameter at the test part is constant when the gas is detected by the detection means. be.

[Example 7] Hereinafter, an example in which the present invention is applied to a flow cytometer will be described in detail with reference to the drawings.

In FIG. 1, 1 is a compressor that is an air generation source.

The air tube connected to this compressor is branched into two branches. And each branched air tube is
The sheath liquid sh
It is connected to a sheath liquid container 5 and a sample liquid container 4 that airtightly store sample liquid Sa. The sheath tube 7 immersed in the sheath liquid sh of the sheath liquid container 5 is guided into the nozzle 20 via the sheath liquid inflow control valve 9.

Further, the sample tube 6 immersed in the sample liquid a in the sample liquid container 4 is guided into the nozzle 20 via the sample liquid inflow control valve 8 . Note that the sample tube is made of a transparent material such as fluororesin.

A flow cell 12 is connected to the upper part of the nozzle 20, and the sample liquid and sheath liquid introduced into the nozzle 20 are
According to the principle of sheath flow, the sample liquid is wrapped in the sheath liquid and converged within the flow cell 12, and each specimen particle in the sample liquid passes through the flow cell 12 one by one. A waste liquid tube 13 is connected to the upper end of the flow cell 12, and the other end is connected to a waste liquid container 14.

Further, 15 is a laser light source that irradiates the sample particles passing through the flow cell 12 with light. Among the optical reactions of the sample particles caused by light irradiation, forward scattered light is photometered by a set of a stopper 16 that cuts direct light, a light receiving lens 17, and a photodetector 18. Further, side scattered light and fluorescence are photometered by a side optical system (not shown).

Near the sample liquid container 4 in the middle of the sample tube 6,
A sensor 10 for detecting air bubbles in the tube is attached,
The output of this sensor 10 is the liquid feeding means]n i-roll circuit 1
9 is connected. Further, a similar sensor 11 is attached to the sample tube section near the nozzle 20, and is connected to a control circuit 19 (liquid feeding means). sensor 10
The internal structure of and 11 is as shown in FIG. 2, and the light from the light emitting diode 21 is transmitted through the sample tube 6 via the aperture 22, and the amount of transmitted light is detected by the photodetector 23. Light transmittance differs depending on whether the sample tube is filled with liquid or air, which manifests itself as a difference in the amount of light detected by the photodetector.

Liquid feeding means] The output signal of the control circuit 19 is connected to the regulators 2 and 3, the sample liquid inflow control valve 8, and the sheath liquid inflow control valve 9, and controls the liquid feeding operation of the sample liquid and the sheath liquid.

Here, if the sample liquid runs out while pressing out the sample liquid by pressurizing the inside of the sample liquid container 4, or if the sample tube 6 is bent inside the container when the sample liquid container is attached, and the tip of the tube comes out above the liquid level. If it is closed, air is sent into the sample tube 6. Since the sample tube 6 is made of a translucent material, the refractive index inside the tube changes due to the sent air, which is detected as a change in the output of the sensor 10. When air in the sample tube is detected in this way, the liquid feeding means] control circuit 1 controls the regulators 2 and 3 to gradually change the sample pressure value and the sheath pressure value, and Control the sample flow diameter so that it is always constant. In this way, even if air enters the sample tube 6, measurement can be continued without deteriorating accuracy. When the delivery of the sample liquid further progresses and air reaches the sensor 11 and is detected by the sensor 11, the liquid feeding means] control circuit controls the regulators 2 and 3 to stop the liquid feeding operation and complete the measurement.

Although the sensor 11 was used to detect the end of the measurement,
A timer may be activated when air is detected by the sensor lO, and the timer may be deactivated after a predetermined period of time during which air will fill the sample tube. In this case, the sensor 11 becomes unnecessary.

Next, a specific method of controlling the regulator will be explained in more detail.

In a circular pipe of radius r and length, the relationship between the pressure difference Δp applied to both ends of the pipe, the height H of the outlet with respect to the pipe inlet, and the liquid flow ff1Q is, when the flow is laminar, t1age
From n-Poiseuille's law, Δp-78=8
vLQ/πr'γ; specific weight of liquid V; viscosity coefficient of liquid.

In the case shown in Figure 1, if h is ignored, (p+
P2)-rH=8 vLQ/re r'
Then, the flow rate Q is: Q= ((P, -P,) -rH) ytr' /8vL
...(1) It is expressed as.

Now, suppose that the sample liquid is consumed and air is sent into the sample tube, resulting in the state shown in Figure 2. Then, the flow iQ changes to Q', and Q' = ((p, -P2) - γ (H-hke)))X
ycr' /8 V (L-, e, t,) -,
,,(2). Therefore, Q' becomes larger than Q, and as a result, the flow diameter becomes thicker. This is because the denominator 1- becomes small as Lj2(t+), and the numerator (PI −p
2) This is because -rH increases to (PI-p2)-γ(Hhfj, l).

Therefore, to keep the sample flow diameter constant, Q must be made equal to Q, which can be achieved by decreasing P with time. This value is determined by experiment or calculation and stored in the device, and the regulator 2 is controlled.

Alternatively, instead of reducing P, P2 may be increased; in this case, the regulator 3 is controlled to increase the pressure of the sheath fluid.

Or, by controlling both regulators 2 and 3 at the same time,
Pl and 22 may be changed at the same time.

Note that Pl may need to be increased depending on the configuration of the device.

The embodiments in which the present invention is applied to a flow cytometer have been described above, but the present invention is not limited to this, and can be applied to a particle counter, a Coulter measuring instrument that measures particulates from the electrical impedance of a sample, or The present invention can be widely applied to devices that sequentially supply samples to a test area, such as a particle measuring device using photoacoustics.

[Effects of the Invention] According to the present invention, in a sample testing device, even if the sample runs out during sample supply and air is sent into the sample tube, the sample can be processed while keeping the sample flow diameter at the test part constant. Since the sample remaining in the tube can be sent to the test area, there is no wastage of sample liquid and highly accurate measurement is possible.

[Brief Description of the Drawings] Figures 1 and 2 are configuration diagrams of an embodiment of the present invention, and Figure 3 is a configuration diagram of a sensor unit. Main symbols in the figures are 1... Compressor 2.3...Regulator 4...Sample liquid container 5...Sheath liquid container, 10.11...Sensor 12...Flow cell 14...Waste liquid container 20... ··nozzle

Claims (1)

[Claims] 1. The end of the sample tube is immersed in a sample liquid container containing a sample liquid, the end of the sample tube is sealed, and the sample liquid is guided into the sample tube by pressurizing the inside of the sample liquid container and directed to the test area. A sample testing device that supplies a sample liquid and tests the sample in the test section, comprising: a detection means provided in the middle of the sample tube to detect gas in the sample tube; and when the detection means detects the gas; A sample inspection device comprising: control means for changing a pressurization value in a sample liquid container so that a sample flow diameter in a test portion is constant. 2. A second detection means for detecting gas in the sample tube is provided in the middle of the sample tube near the test area, and when the second detection means detects gas, the sample feeding operation is stopped. A sample testing device according to claim 1, comprising means. 3. The sample testing device according to claim 1, wherein the control means stops the sample feeding operation after continuing the operation for a predetermined time after the detection means detects the gas.