JPH0293341A - Apparatus for measuring fine particles in liquid - Google Patents

Abstract

PURPOSE:To count particles with high sensitivity by a method wherein a sample liquid is allowed to flow out in a filamentous state from a nozzle and detecting the scattering light from particles at a position sufficiently separated from the center part of said liquid. CONSTITUTION:Sample water is allowed to flow out into the atmosphere in a filamentous state (diameter b) from a nozzle 3. The beam 5 of a laser beam source 4 is throttled by a lens 6 and the counting of fine particles are performed by a beam detector 9 through an irradiation lens 7 and a slit 8 while irradiation position is shifted at every definite distance, for example, 10mum from the center part of the filamentous sample liquid. For example, at the position of 80mum from the center part, only particles having a particle size of 2.0mum are counted. By this method, only flocculated particles or large particles having a certain definite particle size can be counted with high sensitivity.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a device for measuring the agglomerated state of fine particles in a liquid, or a certain amount of fine particles or their aggregates, and more specifically to a quantitative immunoassay. related to immunoassays, blood tests, dust counters, etc.

[Conventional technology]

Using particles coated with antibodies, the concentration of antigen is quantified by determining the aggregation state of those particles, or conversely, using particles coated with antigen and measuring the concentration of antibodies. An example of an apparatus for measuring the state of agglutination in a quantitative immunoassay method such as a method is described in Japanese Patent Publication No. 63-10391. This device measures the light transmittance of the liquid in which these particles are suspended.

[Problem to be solved by the invention]

As described above, the method of measuring the agglomeration state of particles using a light transmission method is not a method of measuring particles individually, so the detection sensitivity of aggregated particles depends on the concentration of non-agglomerated particles. If the 1 degree is high, the detection sensitivity of aggregated particles will be poor.

Therefore, an object of the present invention is to provide an apparatus for separating only particles larger than a certain particle size, such as aggregated particles in the immunoassay, and counting the number with high sensitivity.

[Means to solve the problem]

The above objective is achieved by having a configuration that includes a nozzle for flowing out the sample liquid, an irradiation optical system for irradiating the sample liquid with light, and a detection system that detects scattered light from fine particles in the sample liquid. be done.

That is, the present invention utilizes the fact that in the thread-like liquid flowing out from the nozzle, particles with a smaller particle size are concentrated in the center of the flow than larger particles.

By detecting scattered light from particles at a position sufficiently in front of the center, it is possible to measure only particles with a single large particle size or aggregated particles.

[Effect]

In the thread-like liquid flowing out from the nozzle, particles with smaller diameters are more concentrated in the center of the flow than particles with larger diameters.

〔Example〕

An example is shown in FIG. Nozzle shown as 3 (inner diameter 0.3
nn+, length 25nn+, made of glass) into the atmosphere from sample water (1111 solution of polystyrene particles, two particle sizes 0.8 μm and 2.0 μm manufactured by Dow Chemical Co., each 10-',
The solution diluted 10-6 times) flows out in the form of a thread. According to actual measurements, the diameter of this water system is Q, 36wn. Light 5 emitted from laser light source 4 is focused by lens 6 (beam size 10 μm)
The number of particles was counted by shifting the irradiation position every 10 μm from the center of the sample liquid flowing out in the form of a thread. This data is shown in FIG. The horizontal axis is the irradiation position from the center in the sample liquid flowing like a thread. The vertical axis is the number of counts of detected particles per second. 0 mark means particle size 0.8μ
m, and the ◆ mark is data for a particle size of 2.0 μm.0 Comparing the distributions of both, it can be seen that the smaller the particle size is, the more concentrated it is in the center. All 0.8 μm particles are distributed within 80 μm from the center, so the particle size counted at 80 μm from the center is 2.0 μm.
There are only particles. FIG. 3 shows the change in count value over time at a position 80 μm from the center. 0.8
Counting level when μm particles are flowing (25 particles/
After the addition of 2.0 μm particles, the counting level rapidly increased and reached a constant value (550 particles/second). this is,
indicates that only particles of 2.0 μm are counted.

Since the above-mentioned count value is a count number at a part of the tail of the distribution, it is necessary to perform correction in order to evaluate the sensitivity of particles with a particle size of 2.0 μm. Here, the number of particles falling into the entire water system can be estimated by assuming that the distribution of one particle is a Gaussian distribution.

The above embodiments can be applied to highly sensitive detection of antigens by using polystyrene particles with a particle size of 0.8 μm coated with antibodies. That is, in the presence of an antigen, particles coated with antibodies become a large mass of about 2.0 μm or more due to aggregation.

It is possible to apply the present invention to the detection of this aggregate.

〔Effect of the invention〕

The present invention has made it possible to count only aggregated particles and particles larger than a certain particle size with high sensitivity.

[Brief explanation of drawings]

Fig. 1 is a block diagram of the embodiment, Fig. 2 is an example of measuring particle distribution in a flow path according to the embodiment, and Fig. 3 is a separation needle 1 according to particle size.
There are 1111 examples. 1st item

Claims (1)

[Claims] 1. In a particulate measuring device that detects the characteristics of particulates in a liquid by detecting scattered light from the particulates, there is a means for flowing the sample liquid into the gas from a nozzle in the form of a thread, and a means for removing the center part into this thread-like sample liquid. A particle-in-liquid measuring device comprising: means for irradiating; and means for collecting and detecting scattered light from particles in the thread-like sample liquid.