JPH0262178B2 - - Google Patents

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a particle analysis device, in particular, a particle analysis device that hydrodynamically focuses a cell suspension solution flowing at high speed and irradiates a laser beam to the point, and detects forward scattered light and side scattered light. Alternatively, the present invention relates to a so-called flow cytometer that analyzes the properties and structure of cell particles by sequentially detecting fluorescent light scattered from the side.

(Prior Art) Conventionally, as shown in FIGS. 1 and 2, in a flow cytometer, a cell suspension solution is passed through a flow section 2 in a flow cell 1 together with a surrounding sheath fluid.
The laser beam 4 is caused to flow through the laser beam and focused at a predetermined location 3 hydrodynamically, and the laser beam 4 incident thereon is also optically focused at the location.

The light receiving systems 5 to 8 for forward scattered light, side scattered light, or fluorescent light scattered light are fixedly provided so that the focusing points thereof do not change over time. Note that 5 and 6 are lenses, and 7 and 8 are photodetectors. However, the hydrodynamic focusing point is likely to change over time, and if the hydrodynamic focusing point is displaced in the direction perpendicular to the laser incident direction, that is, in the vertical direction in Figure 2, the following problems may occur. arise.
Specifically, as shown in Figure 3, the laser light intensity has a Gaussian distribution in the direction perpendicular to the laser incidence direction, so the hydrodynamic focusing point is in the direction perpendicular to the laser incidence direction as shown in a to c. If it is displaced, the received light output of side scattered light or fluorescent light scattered light as well as the received light output of forward scattered light will change.

Note that when the hydrodynamic focusing point is displaced in the laser incident direction, it can be considered that the received light output of forward scattered light, side scattered light, or fluorescent light scattered light hardly changes.

(Purpose) In view of the drawbacks of the conventional examples, the present invention is intended to solve the problem of side scattered light, fluorescent light scattered light, It is an object of the present invention to provide a particle analysis device in which the displacement does not affect the received light output of forward scattered light.

(Example) FIG. 4 shows an example of the present invention. Here, the same reference numerals as those already mentioned indicate the same members.

Now, in FIG. 4, the forward scattered light is split by a beam splitter 9 and enters a position detector 10, which detects a positional shift in the hydrodynamic focusing position. As will be described later, the center of the position detector 10 is set in advance at the laser incidence center position, and the hydrodynamic focusing position is detected as the position where the output is minimum, and the amount of positional deviation from the laser incidence center can be determined.

In the present invention, the received light output of side scattered light or fluorescent light scattered light and the received light output of forward scattered light are corrected according to the detected positional deviation amount.

As mentioned above, depending on the hydrodynamic focusing position, that is, the position of the particles, the intensity of the light hitting the particles changes in a Gaussian distribution, so the scattered light detection signals obtained from the photodetectors 7 and 8 are also as shown in FIG. Changes in a Gaussian distribution.

Let I ₀ be the scattered light receiving output obtained when the particle is in its original position, and Id be the scattered light receiving output obtained when the particle is shifted by d in the direction orthogonal to the laser incident direction from this position, then I ₀ / By multiplying and correcting by a coefficient called Id, particle analysis that is not affected by displacement can be performed. This I ₀ /Id is a value that can be known in advance from the Gaussian distribution as shown in FIG. Note that in the case of side scattered light or fluorescent light scattered light, unlike forward scattered light, the light intensity is weak, so the numerical aperture of the receiving lens is large, so its focal depth is shallow, and when the laser light intensity is constant, the laser incidence It is preferable to further multiply by a coefficient for correcting the change in the received light output when shifted in the direction orthogonal to the direction.

Now, the position detector 10 is an optical sensor such as a CCD, and is arranged so that if there is a particle at the center of the flow part, its image will be focused on the center of the position detector 10. The light intensity distribution on 8 is as shown in FIG.

In FIG. 3, a is a photodetection signal when the particle is at position a, that is, at the center of the flow section, and b and c are photodetection signals when the particle is at positions b and c in FIG. 3, respectively.

Since the optical detection signal has a minimum output at the position of the particle, a shift in the position of the particle can be detected. Reference numeral 11 denotes a correction section, which corrects the data of the photodetectors 7 and 8 according to the position of the particle, and stores the corrected data in the storage section 12 one by one.

The stored data is finally displayed on the display section 13 as, for example, histogram data.

Note that in the above embodiment, the beam splitter 9
is provided between the lens 5 and the photodetector 7 in the optical path, but it may also be provided between the flow cell 1 and the lens 5.

In this case, an aperture for receiving forward scattered light is provided between the beam splitter and the lens 5, and a photodetector 7 is provided.
It becomes possible to change the angle of view of light received by the position detector 10.

(Effects) As described above, according to the present invention, highly accurate particle analysis can be performed by measuring the position of the object particle and correcting the photometric amount from that information.

[Brief explanation of the drawing]

Figure 1 is an external view of a flow cell, Figure 2 is an explanatory diagram of a conventional example, Figure 3 is a diagram showing the relationship between test particles in the flow section and laser light intensity distribution, and Figure 4 is an embodiment of the present invention. FIG. 5 is a diagram of the scattered light intensity distribution on the light receiving surface of the photodetector, and FIG. 6 is a diagram of the signal waveform obtained from the position detector. In the figure, 1 is a flow cell, 2 is a flow section, 7, 8
9 is a photodetector, 9 is a beam splitter, 10 is a position detector, 11 is a correction section, 12 is a storage section, and 13 is a display section.

Claims (1)

[Claims] 1. In a particle analysis device that performs particle analysis by irradiating particles near a test position with light having a predetermined intensity distribution and receiving the scattered light or fluorescence, the particle position relative to the test position is determined. A particle analysis device comprising: a position detection section for detecting particles; and a correction section for correcting the output of the received scattered light or fluorescence according to the position of the particle detected by the position detection section. 2. The particle analysis device according to claim 1, wherein the position detection section is provided in an optical path that branches off the optical path of forward scattered light. 3. The particle analysis device according to claim 1, wherein the particles flow one by one in a direction perpendicular to the direction of the irradiation light. 4. The particle analysis device according to claim 3, wherein the detection direction of the position detection section is perpendicular to the irradiation light direction and the particle flow direction.