JPH09230058A - Radioactive sample measuring plate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent light from taking a roundabout between respective wells and attain decrease of cost, in a microplate for measuring a radioactive sample. SOLUTION: This microplate 10 is constituted of a plate body 11 made of opaque material and a transparent thin film 14 stuck on the back of the former. The film 14 functions as the bottom wall of a through hole 13, and hence a well 12 is constituted. The film 14 is thin, and hence a roundabout of light is not generated substantially. A plastic scintillator can be also utilized as the film 14.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the structure of a radioactive sample measuring plate, particularly a microplate.

[0002]

2. Description of the Related Art A microplate known as a radioactive sample measuring plate has, for example, 12 × 8 well-shaped wells. A radioactive sample is placed in each well together with the liquid scintillator, and the radiation generated from the radioactive sample is detected as the light emitted from the liquid scintillator. When detecting such radiation, a pair of photomultiplier tubes are positioned with the light receiving surfaces close to the upper and lower sides of each well, and the light emitted in the well is detected in that state. . Recently, a microplate using a plastic scintillator has also been proposed. In such a microplate, a part or all of the walls forming each well is composed of a plastic scintillator, and the radiation generated in the sample serves as the light emission of the plastic scintillator. To be detected.

[0003]

However, if the entire microplate is formed of a transparent member,
Light wraps around each well, which causes a problem of reduction in measurement sensitivity and a measurement error due to light wraparound.

In this regard, it is conceivable that the side wall (plate body) of the well is made of an opaque material and only the bottom wall of each well is made of a transparent material for light detection, but a different material is used for each well. However, if the bottom wall is provided individually, the manufacturing cost will increase. It is also possible to provide a light shielding material between each well, but the same problem occurs. In particular, since microplates are often used in a disposable system, there is a demand for cost reduction in that sense as well.

Therefore, the plate body is made of an opaque material, a plurality of through holes are formed in the plate body, and a transparent plate is attached to the back surface of the plate body to form a common bottom wall for each through hole. It is conceivable to form a well in this way. However, although such a configuration has an advantage in terms of manufacturing cost, there is a problem that light enters in the surface direction of the transparent plate and crosstalk occurs between the wells.

The present invention has been made in view of the above conventional problems, and an object thereof is to provide a radioactive sample measuring plate capable of sufficiently reducing light from entering between wells and reducing the manufacturing cost. Especially.

[0007]

In order to achieve the above object, the present invention provides a plate body having at least one through hole, and a transparent film bonded to the entire back surface of the plate body. , And the film forms the bottom of each through hole to form a well, and a radioactive sample is placed in the well.

According to the above structure, a thin film is attached to the entire back surface of the plate body, and the film serves as a bottom wall common to the through holes, thereby forming wells. According to the present invention, the bottoms of a plurality of wells can be easily formed at the same time simply by attaching a film, so that the manufacturing cost can be reduced. Of course, in the plate body, at least the side wall of each well is made of an opaque material, so that no light leaks from that part. In this case, the entire plate body is preferably made of an opaque material. In addition, since the film is thin, it is possible to substantially ignore the surrounding of light and effectively prevent crosstalk even on that side, and the detection sensitivity is enhanced as a reflective effect thereof.

In a preferred aspect of the present invention, the film is made of a material containing a plastic scintillator. With this configuration, it is not necessary to add a liquid scintillator to the sample, and quenching, which is a problem peculiar to the liquid scintillator, can be prevented. The film is preferably adhered to the back surface of the plate body by heat fusion.

In a preferred aspect of the present invention, a protruding edge portion is formed in the lower opening of the through hole. With this configuration, the protruding edge portion can enhance the degree of close contact with the film, and can improve the airtightness of each well. In the plate body, at least the well side surface,
The detection sensitivity can be further improved by using a member that reflects light well.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows a preferred embodiment of the radioactive sample measuring plate according to the present invention.
Microplate 1 as a plate for measuring radioactive samples
A partial sectional view of 0 is shown. As shown in FIG. 2, a plurality of wells 12 for containing a radioactive sample are formed in the microplate 10, and for example, 12 × 8 wells 12 are two-dimensionally formed.

Returning to FIG. 1, the microplate 10 of this embodiment is roughly divided into a plate body 11 and a film 14 attached to the entire back surface of the plate body 11. A plurality of through holes 13 forming each well 12 are formed in the plate body 11, and the bottom wall of the through holes 13 is formed by bonding the film 14 to the entire back surface of the plate body 11. . That is, the film 14 forms a common bottom surface of each well 12. The diameter of the well 12 is, for example, 7 mm,
The depth of the well 12 is 12 mm, for example. Film 1
Reference numeral 4 is a transparent member having a thickness such that light wraparound in the plane direction is substantially negligible, and is made of, for example, a polyethylene material having a thickness of 20 μm.

When the radioactive sample is measured by the microplate 10 configured as described above, first, the radioactive sample 18 is put in the well 12 of the microplate 10, and the liquid scintillator is put together with the radioactive sample 18. A pair of photomultiplier tubes 16 are arranged close to each other on the upper side and the lower side of the microplate 10 with their light receiving surfaces facing the wells 12, and radiation is detected in this state. That is, the radiation generated in the sample 18 causes the liquid scintillator to emit light, and the light generated thereby is detected by the photomultiplier tube 16 arranged above or the light passing through the transparent film 14 is detected. Photomultiplier tube 16 arranged on the lower side
It is detected by. The outputs of these photomultiplier tubes 16 are input to the coincidence counting circuit.

Although the above description relates to the measurement of a radioactive sample by the liquid scintillator system, the film 14 may be made of a plastic scintillator or a material containing a plastic scintillator, for example. In this case, it is not necessary to mix the liquid scintillator with the sample 18, and quenching, which is a problem peculiar to the liquid scintillator, can be avoided. Even when the film 14 is composed of a plastic scintillator,
Its thickness is extremely thin, and the problem of crosstalk between wells does not substantially occur.

The plate body 11 is made of an opaque material, for example, white or black polypropylene or the like. Of course, if at least the side wall of the well 12 is opaque, the problem of crosstalk between wells can be prevented. Therefore, for example, a light reflecting layer may be formed on the side surface of the well 12.

The film 14 is joined to the plate body 11 by using, for example, heat fusion. In this case, for example, as shown in FIG. 3, a ring-shaped protruding edge portion slightly protruding downward is formed in the lower opening of the through hole 13 in the plate body 11, and the protruding edge portion 13 </ b> A forms a protrusion with the film 14. You may improve adhesiveness. With this configuration, the airtightness of each well 12 can be further improved, and problems such as leakage of the sample between the wells 12 can be effectively prevented.

After the measurement of the radioactive sample, the microplate 10 is discarded if necessary. In this case, the film 14 is discarded while being bonded to the plate body 11. Of course, if necessary, the film 14 may be separated from the plate body 11 and discarded individually.

According to the above-described embodiment, there is an advantage that the cost of the microplate can be reduced, and the measurement sensitivity can be prevented from being lowered by preventing the light from flowing between the wells. Further, according to the present invention, there is an advantage that the airtightness of the bottom portion of each well can be further improved and a highly reliable microplate can be provided.

[0020]

As described above, according to the present invention,
It is possible to sufficiently reduce the wraparound of light between the wells and to reduce the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a partial cross-sectional view of a radioactive sample measurement plate according to the present invention.

FIG. 2 is a top view of a radioactive sample measurement plate according to the present invention.

FIG. 3 is a cross-sectional view showing an embodiment in which a protruding edge portion is provided below a through hole.

[Explanation of symbols]

10 microplate, 11 plate body, 12
Well, 13 through hole, 14 film, 13A protruding edge.

Claims (4)

[Claims] 1. A plate body having at least one through hole formed therein, and a transparent film bonded to the entire back surface of the plate body, wherein the film forms the bottom of each through hole. A plate for measuring a radioactive sample, wherein a well is formed and a radioactive sample is placed in the well. 2. The radioactive sample measuring plate according to claim 1, wherein the film is made of a material containing a plastic scintillator. 3. The radioactive sample measuring plate according to claim 1, wherein the film is adhered to the back surface of the plate body by heat fusion. 4. The radioactive sample measuring plate according to claim 1, wherein a protruding edge portion is formed at a lower opening of the through hole.