JPH0641955B2 - Two-layer sample separator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for sorting a sample composed of two layers by a suction nozzle.

For example, when separating plasma and blood cells from a sample consisting of two layers of plasma and blood cells obtained by centrifugation, the quantitative ratio of plasma and blood cells present in the two layers in the same sample container is Since they are different, it is advantageous to detect not only the liquid surface of the sample but also the boundary surface between plasma and blood cells in order to separate them separately.

FIG. 1 shows a schematic configuration of an example of a conventional liquid surface detection electrode. In this conventional example, a non-conductive nozzle 1 for sample sorting is used, and two conductors 2 and 2'along the tube axis direction are attached to the tip of the nozzle as counter electrodes. When using such a conventional nozzle with a liquid level detection electrode to collect a sample composed of two layers,
The impedance change at the boundary surface cannot be detected accurately. There is a drawback that the two layers of liquid cannot be separated separately.

An object of the present invention is to solve the above-mentioned drawbacks and to provide an apparatus capable of separately separating a desired amount of a two-layer sample composed of, for example, plasma and blood cells.

A two-layer sample collecting device according to the present invention is a device for collecting upper-layer plasma and lower-layer blood cell samples from a sample container accommodating two-layer samples having different impedances. According to the depth of the liquid surface to be detected on the outer surface of the nozzle, two nozzle-cum-electrodes, each of which has only a desired height part left as an electrode part and the other part is covered with an insulating coating, A liquid level detection device for identifying a voltage change between electrode parts formed on both of the dual-purpose electrodes;
A vertical drive device for integrally moving the nozzle-cum-electrode together up and down, and the plasma is sucked by one nozzle-cum-electrode after detecting the liquid level of plasma in the sample container by the two nozzle-cum-electrodes, Next, the vertical driving device is driven to lower the two nozzle / combined electrodes, and after the two nozzle / combined electrodes detect the blood cell surface, the other nozzle / combined electrode sucks blood cells. It is a thing.

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 2 shows the constitution of different embodiments of the liquid boundary surface detection electrodes used in the sorting apparatus according to the present invention.

In each of FIGS. A, B and C, the nozzle 4 is formed of a conductive material and is used as a part of a lead wire in the form of a nozzle-cum-electrode. In addition, A and B in the figure
Is a front view and C is a cross-sectional view.

In FIGS. 2A, 2B, and 2C, a portion 5 of the conductive nozzle 4 that serves as a liquid detection electrode portion is exposed as a conductive portion
The other portion is provided with an insulating coating 6 made of, for example, insulating paint or Teflon.

That is, in the figure A, the tip of the conductive nozzle 4 is exposed, and in the figure B, the portion above the tip is exposed as the electrode portion 5, and the remaining portion is exposed by the insulating coating 6. The electrode also serves as a nozzle, and the position of the electrode portion 5 is appropriately set according to the depth of the liquid surface to be detected. The electrode shown in FIG. 6C is a nozzle-combined electrode having a structure in which the inner surface of the conductive nozzle 4 is left as the electrode portion 5 and the outer surface is covered with the insulating coating 6.

FIG. 3 is a diagram showing the configuration of an embodiment of the present invention.
In this embodiment, the two nozzle-combined electrodes 7, 7'having the structure shown in FIG. 2A are used, and the electrode portions 5, 5 formed at the tips of the two nozzle-combined electrodes 7, 7'are used. 5'is used as an opposite electrode to detect the boundary surface of the liquid in the sample container 14, for example, the sample.

A feature of the sorting apparatus of the present invention is that the boundary surface of each liquid layer of a sample having two layers of conductive samples having different impedances can be detected, sorted and sorted.

Now, it is assumed that the sample container 14 contains a sample composed of two layers 15 and 16 having different impedances, such as a sample composed of a plasma layer and a blood cell layer obtained by centrifugation. To do.

When the nozzle-cum-electrodes 7, 7'are lowered by a nozzle up-and-down driving device (not shown) and the conductive portions 5, 5'of both nozzle-cum-electrodes 7, 7'are immersed in the conductive liquid 15 in the upper layer, the power supply 12
The liquid level of the liquid 15 in the upper layer is detected by the voltage generated in the series resistor 11 by. Liquid level detection device based on the detection voltage at this time
The upper layer liquid 15 can be sucked by actuating 13 and using one of the nozzle / electrodes shown as 7, for example, 7. Further, the nozzle / electrodes 7 and 7'are lowered so that the electrode portions 5 and 5'at the tips of the nozzle / electrodes 7 and 7'are the lower liquid layer 16.
When soaked in liquid, the lower liquid layer 16 and the upper liquid layer
Since the impedance is different from that of 15, the voltage generated in the series resistance 11 changes. By discriminating this voltage change by the liquid level detection device 13 and aspirating the sample by the other electrode also serving as a nozzle 7'according to the discrimination result, the lower layer liquid 16 can be fractionated and fractionated.

As described above, according to the present invention, the change in impedance is detected at the electrode portion, and the samples of the upper layer and the lower layer are sucked by the separate nozzle-cumulative electrodes. Can be collected. Further, an electrode portion was formed without applying an insulating coating only to a desired portion of the conductive nozzle where the electrode action is desired, and an electrode having the other portion coated with an insulating coating was used as a liquid boundary surface detecting electrode. Therefore, the electrode portion can be selected at any position. Therefore, it is possible to suck the liquid at an arbitrary depth from the liquid surface. Moreover, since most of the conductive members that form the electrodes are covered with the insulating coating, there are few portions that come into contact with the sample or the chemical solution, and therefore corrosion resistance of the electrodes can be improved by using a suitable insulating coating material such as Teflon. Not only does the durability increase, but dirt is less likely to adhere, cleaning is easier, and lead wires can be easily routed. Since only the part to be exposed is exposed and the remaining surface is covered with an insulating coating, the nozzle can also function as an electrode, so it is small and lightweight, yet has both functionality and corrosion resistance. An excellent liquid fractionation device can be expected.

[Brief description of drawings]

FIG. 1 is a block diagram showing an example of a conventional liquid level detecting electrode, and FIGS. 2A, 2B and 2C are block diagrams showing different examples of the liquid interface detecting electrode used in the fractionation device according to the present invention, and FIG. FIG. 1 is a diagram showing a configuration of an example of a sorting device according to the present invention. 4 ... Conductive nozzle, 5, 5 '... Electrode part 6 ... Insulating film, 7, 7' ... Nozzle / electrode 11 ... Series resistance, 12 ... Power supply 13 ... Liquid level detector, 14 ... Sample container 15, 16 ... Sample Layers with different impedances

Claims (1)

[Claims] 1. A liquid surface for detecting the outer surfaces of two conductive nozzles in a device for separating upper layer plasma and lower layer blood cell sample from a sample container containing a sample composed of two layers having different impedances. Depending on the depth of each of the nozzles, only the desired height part is left as an electrode part and the other parts are covered with an insulating coating, and the electrode part formed on both the nozzle and electrode. And a vertical drive device that integrally moves the two nozzle-cumulative electrodes up and down, and the liquid level of plasma in the sample container is provided by the two nozzle-cumulative electrodes. Blood plasma is sucked by one of the nozzle / combined electrodes, and then the up / down drive device is driven to lower the two nozzle / combined electrodes, and after the two nozzle / combined electrodes detect the blood cell surface,
A sample collecting device comprising two layers, wherein blood cells are sucked by the other electrode also serving as a nozzle.