JPS63300940A - Particle analyzing device - Google Patents

Abstract

PURPOSE:To adjust the quantity of light incident on a photoelectric detector corresponding to the intensity of forward scattered light by providing a means which adjusts the quantity of light incident on the photoelectric detector according to the intensity of light scattered by particles to be inspected. CONSTITUTION:Laser light L passes through an image formation optical system 2 and is projected on the particles to be inspected which flow in the communication part 3a of a flow cell 3, and the resulting forward scattered light passes through a convergence lens 5 and is incident on a halfmirror 7. Then, the scattered light after being reflected by the mirror 7 enters the photoelectric detector 9 and is converted into an electric signal, which is inputted to an arithmetic circuit 10 to calculate the quantity of scattered light passing through the mirror 7 from the quantity of the light incident on the photoelectric detector 9; and one of ND filters on an ND filter plate 8 is selected so that the detector 6 is not saturated, and moved by a driving circuit 11 on the optical axis 0. Thus, the means which adjusts the quantity of light incident on the detector 6 is provided to accurately measure the intensity of the light scattered by the particles to be inspected without saturating the detector 6.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a particle analysis device used in a flow cytometer or the like, which analyzes the properties of sample particles by detecting scattered light and fluorescence from the sample particles. It is.

[Conventional technology] A flow cytometer is a cell suspension solution that flows at high speed.
In other words, it is a device that elucidates the properties and structure of cells by irradiating a sample liquid with, for example, a laser beam and detecting a photoelectric signal from the scattered light and fluorescence.It is used in cytochemistry, immunology, hematology, oncology, genetics, etc. used in the field of

In conventional particle analysis devices used in flow cytometers, for example, 200 gm
Inside the flow section with a minute rectangular cross section of 200 lm,
Laser light or other light is irradiated onto test particles such as blood cells that pass through the sheath fluid, and the resulting forward and side scattered light is used to determine the shape, size, and shape of the test particles.
It is possible to obtain particle-like properties such as refractive index. Also,
For test particles that can be stained with a fluorescent agent, important information for analyzing the test particles is obtained by detecting the fluorescence of the test particles from side scattered light in a direction almost perpendicular to the irradiation light. be able to.

FIG. 2 is a configuration diagram of a conventional particle analysis device, in which an imaging optical system 2, a flow cell 3, a light shielding plate 4, a condensing lens 5, and a photoelectric detector 6 are sequentially arranged along the optical axis O from a laser light source 1. The particles to be detected flow in a direction perpendicular to the plane of the paper through a flow section 3a provided at the center of the flow cell 3. Further, the imaging optical system 2 is, for example, an optical system in which the axes of two cylindrical lenses are arranged orthogonally to each other.

A laser beam emitted from the laser light source 1 is formed into an elliptical beam having an arbitrary major axis and minor axis in the imaging optical system 2, and is irradiated onto the test particles flowing through the flow section 3a of the flow cell 3. The laser beam that is not scattered by the test particles is blocked by the light shielding plate 4, and the light scattered by the test particles enters the photoelectric detector 6 via the condenser lens 5, where it is converted into an electrical signal according to the light intensity. Ru.

Generally, the intensity of forward scattered light is proportional to the diameter of the test particle, so it is possible to calculate the diameter of the test particle from the obtained light intensity. 4
1, there is a problem that the output of the photoelectric detector 6 becomes saturated and measurement becomes impossible.

For this reason, in conventional particle analyzers, in order to prevent the output of the photoelectric detector from becoming saturated, it is necessary to
A D filter is arranged and the measurement is performed while adjusting the amount of light incident on the photoelectric detector 6.

However, in this method, when adjusting the amount of light incident on the photoelectric detector 6, there is a risk that an excessive amount of light may enter the photoelectric detector 6, which may damage the photoelectric detector 6 and shorten its lifespan. It turns out. In addition, this method requires replacing the NDD filter in accordance with the amount of light incident on the photoelectric detector 6, which has the drawback that not only is there a possibility of erroneous operation, but the work efficiency is reduced.

[Object of the Invention] An object of the present invention is to provide a particle analysis device capable of eliminating the drawbacks of the conventional example and adjusting the amount of light incident on a photoelectric detector in accordance with the intensity of forward scattered light. be.

[Summary of the Invention] The gist of the present invention for achieving the above-mentioned object is to include an irradiation optical system that irradiates a light beam onto specimen particles, and a detection optical system that includes a photoelectric detector that detects light scattered by the specimen particles. have,
The particle analysis apparatus is characterized by comprising means for adjusting the amount of light incident on the photoelectric detector according to the intensity of light scattered by sample particles.

[Embodiments of the Invention] The present invention will be explained in detail based on the embodiment shown in FIG.

Fig. 1 shows an embodiment of the present invention, and members with the same symbols as those in the conventional example shown in Fig. 2 indicate the same members and have the same functions. A half mirror 7 and an ND filter plate 8 are disposed obliquely on the optical axis O between the condensing lens 5 and the photoelectric detector 6 in the conventional example shown in FIG. The output of the photoelectric detector 9 is connected to an arithmetic circuit 10 and a drive circuit 11.
are sequentially connected to the drive circuit 11, and the ND filter plate 8 is driven by the output of the drive circuit 11.

The half mirror 7 has a characteristic of, for example, reflecting 5% of the amount of incident light and transmitting the remaining 95%.An NDD filter is attached to the ND filter plate 8, and the drive circuit 1
1, one of the plurality of NDD filters is moved onto the optical axis O.

In the particle analysis apparatus configured in this way, the laser beam emitted from the laser light source 1 is transmitted through the imaging optical system 2.
The forward scattered light from the test particles enters the half mirror 7 via the condenser lens 5. The scattered light reflected by the half mirror 7 enters the photoelectric detector 9, converts it into an electrical signal, and then inputs it to the arithmetic circuit 10. Then, in the arithmetic circuit 10, the amount of scattered light passing through the half mirror 7 is calculated from the amount of light incident on the photoelectric detector 9, and one of the plurality of NDD filters on the ND filter plate is calculated so that the photoelectric detector 6 is not saturated. is selected and moved onto the optical axis O by the drive circuit 11. This makes it possible to measure the intensity of the forward scattered light without the photoelectric detector 6 becoming saturated.

In the embodiment described above, the amount of light incident on the photoelectric detector 6 is adjusted using an ND filter, but it is also possible to use a liquid crystal element that can electrically change the transmittance of each region. It is. In addition, by adjusting the amount of light incident on the photoelectric detector 6 of the forward scattered light, the photoelectric detector 6
However, since the photoelectric detector may be similarly saturated with side scattered light, the same effect can be obtained by applying the present invention.

Furthermore, in the embodiment described above, the half mirror 7 and the ND
Although the filter plate 8 is disposed between the condenser lens 5 and the photoelectric detector 6, it may be disposed at any other position as long as it is on the optical axis O between the flow cell 3 and the photoelectric detector 6. Alternatively, the amount of light incident on the photoelectric detector 6 may be controlled by the output of the photoelectric detector 6 without using the half mirror 7 or the photoelectric detector 9.

Further, in the embodiment, a light amount adjusting means was provided in the detection optical system, but
It may be provided in the irradiation optical system including the laser light source 1.

[Effects of the Invention] As explained above, the particle analysis device according to the present invention prevents the photoelectric detector from becoming saturated by providing a means for adjusting the amount of light incident on the photoelectric detector, and reduces the amount of light scattered by the particles to be detected. This has the effect of being able to accurately measure the strength of

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of a particle analysis apparatus according to the present invention, and FIG. 2 is a block diagram of a conventional example. Symbol l is a laser light source, 2 is an imaging optical system, 3 is a flow cell, 4 is a light shielding plate, 5 is a condensing lens, 6 is a photoelectric detector, 7
The half mirror 18 is an ND filter plate, 9 is a photoelectric detector, 10 is an arithmetic circuit, and 11 is a drive circuit.

Claims (1)

[Scope of Claims] 1. A detection optical system including an irradiation optical system that irradiates the sample particles with a light beam and a photoelectric detector that detects the light scattered by the sample particles, A particle analysis device characterized by comprising means for adjusting the amount of light incident on the photoelectric detector accordingly. 2. The particle analysis device according to claim 1, wherein the means for adjusting the amount of light is an optical filter. 3. The particle analysis device according to claim 1, wherein the means for adjusting the amount of light is a liquid crystal element.