JPS631952A - Particle analyser - Google Patents

Abstract

PURPOSE:To accurately analyze a particle to be inspected, by scanning the particle to be inspected in the direction crossing the flow of the particle at a right angle by a beam scanning apparatus and detecting scanning beam by a beam receiving element. CONSTITUTION:The laser beam L from a laser beam source 1 is incident to an acoustooptical element 3 and zero order beam advances straightly to be cut by a stopper 8. Then, a modulation signal is applied to the element 3 to scan the laser beam L, for example, at an angle theta and the scanning beam is allowed to irradiate the particles S to be inspected flowing through the flow part 1a of a flow cell 5 by an image forming lens 4. When the angle theta is selected by scanning the beam L so that the position of the particles S is necessarily detected even when said particle moves in the scanning direction, an irradiation condition becomes same. Since a stopper 5 is formed into a long shape in the scanning direction, the direct beam in the scanning direction can be cut. The beam scattered by the particles S is shifted from the stopper 5 to be incident to a beam detector 7 by a condensing lens 6. Said forward scattering beam generally imparts the size information of the particle to be inspected on a basis of a Nie scattering theory.

Description

[Detailed Description of the Invention] "Industrial Application Field" The present invention is a flow cytometer, etc., in which scanning light is directed at test particles suspended in a high-speed fluid and light scattered by the test particles is detected. In particular, the present invention relates to a particle analysis device that measures the size of particles to be detected.

[Prior Art] In a conventional particle analysis device used in a flow cytometer or the like, a particle size of, for example, 200 m x 20
Irradiation light is irradiated onto the test particles passing through the flow section with a minute cross section of 0 JLm while being wrapped in sheath liquid, and the resulting forward and side scattered light is used to determine the shape and shape of the test particles.
It is possible to obtain particle-like properties such as size conflict refractive index.

Conventionally, this type of device measures the size of a sample particle by detecting forward scattered light caused by a fixed light beam traversing the sample particle flowing in a fluid. However, the intensity of the scattered light is not constant because the position where the particles to be inspected flow through the fluid is relatively shifted from the intensity In of the light beam and the amount of light hitting the particles to be inspected changes. sheath flow J
By adopting J:, this drawback can be compensated to a considerable extent, but it is essential to accurately align the center of the flow with the center of the intensity distribution of the light beam in advance.

[Object of the Invention] An object of the present invention is to provide a particle analysis device that scans a test particle with a light beam, detects the forward scattered light, and determines the shape of the test particle.

[Summary of the Invention] The gist of the present invention for achieving the above-mentioned object is to provide an apparatus for measuring the shape of particles to be inspected by irradiating light from a light source to particles to be inspected flowing in a fluid. This particle analysis device is characterized in that particles to be detected are scanned in a direction perpendicular to the flow and detected by a light receiving element.

[Embodiments of the invention] The present invention will be explained in detail based on illustrated embodiments.

In FIG. 1, reference numeral 1 denotes a flow cell, and a sample containing test particles is flowed through a flow section 1a provided in a direction perpendicular to the drawing. In this circulation part 1a, a laser beam L from a laser light source 2 passes through an acousto-optic element 3 and an imaging lens 4.
It is designed to be incident through the Also, on the opposite side of the incident beam, a stopper 5, a condensing lens 6, and a photodetector 7 are provided.
is located. As shown in FIG. 2, the shape of the stopper 5 is a strip that crosses the center of the condenser lens 6. Note that a stopper 8 is provided behind the acousto-optic element 3 in the straight direction of the laser beam L.

A laser beam L from a laser light source 1 enters an acousto-optic element 3, and zero-order light travels straight and is cut by a stopper 8. By adding a modulation signal to the acousto-optic element 3, the laser beam L is scanned at a scanning angle θ as shown.

This is irradiated by the imaging lens 4 onto the test particles S flowing through the flow section 1a of the flow cell 5. By scanning the laser beam L, even if the position of the particle S to be inspected moves in the scanning direction, the irradiation conditions remain the same if the scanning angle θ is selected so that it is always detected. Since the stopper 5 has a long shape in the scanning direction, it can cut direct light in the scanning direction.

The light scattered by the test particles S leaves the stopper 5 and enters the photodetector 7 through the condensing lens 6. Since the forward scattered light generally reflects the size of the test particle S according to the theory of Hie scattering, information on the size of the test particle S can be obtained.

It is preferable that the scanning angle θ by the acousto-optic element 3 is set to such an extent that the laser beam L does not hit the edge of the flow section 1a. Although not shown, it is set in a direction approximately 90" different from the forward scattered light detection direction. Similarly to conventional particle analysis devices, it is also possible to arrange a condensing optical system in the particle analyzer and measure the side scattering and fluorescence of the particles S to be examined.When the laser beam L is made incident on the acousto-optic element 3 , a beam size changing lens system may be inserted between them to change the beam size.

Note that by setting the focal position of the imaging lens 4 as the beam exit point of the acousto-optic system 3, the imaging lens 4 and the condensing lens 6
It is desirable to use a telecentric optical system between the two and irradiate parallel light onto the particles S to be measured to stabilize the measurement conditions.

[Effects of the Invention] As explained above, the particle analysis device according to the present invention irradiates the test particles with a beam while scanning, so that even if the positions of the test particles in the flow vary, for example, the peak By detecting the area, accurate analysis of the particles under test is possible, and the alignment accuracy of the center of intensity of the irradiation light and the center of the sample flow is increased, reducing the influence on measurements compared to conventional methods. Ru.

[Brief explanation of the drawing]

The drawings show an embodiment of the particle analysis device according to the present invention, with FIG. 1 being a configuration diagram thereof, and FIG. 2 being an explanatory diagram of the relationship between a condenser lens and a stopper. Reference numeral 1 is a flow cell, la is a flow section, 2 is a laser light source, 3 is an acousto-optic element, 4 is an imaging lens, 5 is a stopper,
6 is a condensing lens, and 7 is a photodetector.

Claims (1)

[Claims] 1. In an apparatus for measuring the shape of particles to be detected by irradiating light from a light source to the particles to be detected flowing in a fluid, the particles to be detected are moved in a direction perpendicular to the flow using a light scanning means. A particle analysis device characterized by scanning and detection using a light receiving element. 2. Claim 1, wherein the light source is a laser light source
Particle analysis device described in section. 3. The particle analysis device according to claim 1, wherein the optical scanning means is an acousto-optic deflection element. 4. The particle analysis device according to claim 1, further comprising a stopper having a long side in the optical scanning direction in front of the light receiving element.