JP2001059812A - Weak light measuring apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a weak light measuring apparatus capable of being suitably used in the measurement of the weak light emitted from an organism specimen. SOLUTION: The weak light measuring apparatus 11 is constituted of a chamber 21, a sample container 31, a light receiving element 51, an optical system 61 and a thermostatic pump 71. A cooling agent is introduced into the chamber 21 to cool the chamber down to predetermined temp. A constant temp. fluid is introduced into the sample container 31 by the thermostatic pump 71 to be held to production temp. After temp. conditions are set, the weak light emitted from the organism specimen S is measured. By this apparatus 11, the backlight caused by heat radiation can be suppressed while holding the function of the organism specimen S, and highly accurate measurement becomes possible.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a faint light measuring device, and more particularly to a faint light measuring device for a biological sample for suitably measuring faint light emitted from singlet oxygen in a biological sample or the like.

[0002]

2. Description of the Related Art The technology for measuring weak light is applied not only to astronomy but also to a wide range of fields such as biology. In the field of biology, a method of measuring weak light emitted from a substance is used to elucidate the generation mechanism of a substance existing in a living body or to search for a moving path of the substance. Such techniques are being applied to various fields in the field of biology, and in particular, the establishment of a technique for measuring the weak light emitted from singlet oxygen, which is expected to have a significant effect on living organisms, is expected. .

[0003] Since the light emitted from singlet oxygen is very weak, high accuracy is required to measure it. For example, JP-A-10-206313 and JP-A-11-10
No. 1686 discloses a weak light detection device for detecting weak light from singlet oxygen in a biological sample. In these detection devices, the sample to be measured is stored in one of the two sample containers, and the dummy sample is stored in the other, and the light emission from each sample is detected by the two detectors, and the difference between the two is taken as a singlet. Measure the faint light from oxygen.

[0004]

However, the weak light emitted from singlet oxygen is near-infrared light having a wavelength of about 1.27 μm. In such a near-infrared region, a background object such as a measuring container is used. Since the heat radiation from the light source becomes a large noise source, the S / N ratio is lowered, and it is difficult to measure the weak light with high accuracy. Further, in the conventional apparatus using the difference between the sample to be measured and the dummy sample, the measurement result includes an error due to a difference in the state of the sample or the accuracy of the detector because the sample and the detection system are not necessarily the same. It was likely.

As described above, the conventional measuring apparatus cannot sufficiently remove the influence of the background light, and it is almost impossible to measure very weak light such as light emission from singlet oxygen with high accuracy. It was possible.

An object of the present invention is to solve the above-mentioned problems and to provide a weak light measuring device capable of measuring weak light with high accuracy. In particular, the present invention is suitable for suitably detecting weak light from singlet oxygen in a biological sample or the like. It is an object of the present invention to provide a faint light measuring device capable of measuring.

[0007]

According to the present invention, there is provided a weak light measuring apparatus comprising: a sample container having an emission portion for emitting light emitted from a sample housed therein; and at least condensing light emitted from the emission portion. An optical system including light collecting means, a light receiving element for receiving light collected by the optical system, and an outer container having heat insulation, airtightness, and light shielding properties, and including a sample container, an optical system, and a light receiving element therein And a cooling means for cooling the inside of the external container to a first temperature, and a temperature holding means for holding at least a temperature of a sample peripheral portion inside the sample container at a second temperature. According to this device, by cooling each part of the device to a predetermined temperature, heat radiation from a background object other than the sample can be almost completely suppressed, and the measurement accuracy of weak light from the sample can be improved. In addition, by maintaining the inside of the sample container at a predetermined temperature, an environment suitable for the sample to be measured can be maintained.

In order to suppress the heat radiation from each part of the apparatus to the extent that high-precision measurement of weak light is possible, the first temperature must be 10
It is preferable that the temperature is not higher than ° C. In addition, in order to prevent dew formation on the light receiving surface of the light receiving element, it is preferable to further include a cooling unit that cools the light receiving element to a temperature equal to or lower than the first temperature. The cooling means for cooling to the first temperature and the means for cooling the light receiving element are preferably means using liquid nitrogen or its vapor from the viewpoint of simplicity and the like.

The sample container is preferably a container having heat insulation and airtightness. In this case, the sample peripheral portion and the outside of the sample container are insulated from each other and can be maintained at different temperatures. In order to ensure the heat insulation, the sample container is preferably a container having a double structure. Further, in order to reduce the temperature of the outer surface of the sample container and prevent heat radiation from the outer surface of the sample container, it is preferable that the outer surface of the sample container except for the emission part is coated with a metal. Further, the sample container preferably has a spherical structure (a so-called integrating sphere structure). In this case, weak light emitted from the sample can be efficiently emitted.

When the sample to be measured is a sample collected from a living body, the second temperature is set to 1 to maintain the function of the biological sample.
The temperature is preferably in the range of 0 ° C to 40 ° C. In addition, it is preferable to provide a temperature sensor that senses at least the temperature of the periphery of the sample inside the sample container so that the temperature of the periphery of the sample can be grasped and set accurately.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a weak light measuring device according to the present invention will be described below with reference to the drawings. In addition,
The same or corresponding parts are denoted by the same reference numerals, and redundant description will be omitted.

FIG. 1 is a conceptual diagram of a first embodiment of a weak light measuring device according to the present invention as viewed from a cross section. The weak light measurement device 11 according to the present embodiment includes a chamber 21, a sample container 31, a light receiving element 51, an optical system 61, and a constant temperature pump unit 71.

The chamber 21 is a box-shaped external container having heat insulation, airtightness, and light shielding properties, and is an inlet for introducing a coolant (in the present embodiment, liquid nitrogen or its vapor) into the chamber. 23 and an outlet 25 for discharging the coolant from the inside of the chamber. Inlet 23
The outlet 25 is connected to a cooling system (not shown).

The sample container 31 is a box-shaped container having heat insulation and airtightness, and has an emission window 33 for transmitting light, an introduction port 35 for introducing a constant temperature fluid, and a discharge port for extracting the constant temperature fluid. An outlet 37 is provided at a predetermined position in the chamber 21. The inlet 35 is connected to one end of a heat-insulating channel 39 that penetrates the wall surface of the chamber 21,
The outlet 37 is connected to one end of a heat-insulating channel 41 that penetrates the wall of the chamber 21.

The light receiving element (in this embodiment, a photomultiplier tube (PMT)) 51 has sensitivity to light of a predetermined wavelength (in this embodiment, about 1.27 μm), and It is installed at a predetermined position in 21. This light receiving element 51 is connected to an external storage means (not shown) via a conductive cord (not shown).

The optical system 61 is composed of one or more condenser lenses 63 for condensing light and an optical filter 65 for selectively transmitting light of a predetermined wavelength. Is set in the chamber 21 so that the light is focused on the light receiving surface of the light receiving element 51. In the present embodiment,
The two condenser lenses 63 and the optical filter 65 positioned between them are provided with the exit surface of the exit window 33 and the light receiving element 5.
3 are arranged in parallel with the light receiving surface.

The constant temperature pump 71 has an inlet 73 for introducing a fluid and an outlet 75 for extracting a constant temperature fluid.
And installed outside the chamber 21. The outlet 75 is connected to the other end of the heat insulating channel 39.

Next, the operation of the weak light measuring device 11 will be described. First, the inlet 23 and the outlet 25 are opened, and a predetermined flow rate of the coolant circulates in the chamber 21. Accordingly, the inside of the chamber 21 except for the inside of the sample container 31 has a predetermined temperature (−10 in the present embodiment).
° C), and heat radiation from sources other than the sample can be suppressed. On the other hand, the outlet 75, the inlet 35, and the outlet 3
7 is opened, the fluid introduced from the introduction port 73 is set to a predetermined constant temperature (37 ° C. in the present embodiment) in the constant temperature pump unit 71, and the heat insulating flow path 39 and the heat insulating flow path 4 are set.
1 circulates in the sample container 31. by this,
The inside of the sample container 31 is maintained at a predetermined constant temperature, so that the function of the biological sample during the measurement can be maintained.

After each part of the apparatus 11 is set at a predetermined temperature as described above, the weak light emitted from the singlet oxygen in the biological sample S contained in the sample container 31 is measured with high accuracy. . That is, (1) weak light emitted from singlet oxygen passes through the exit window 33 and exits outside the sample container 31. (2) The light is condensed in parallel by the first condenser lens 63. (3) The light is split by the optical filter 65 into a predetermined wavelength (about 1.27 μm). (4) The light is condensed on the light receiving surface of the light receiving element 51 by the second condenser lens 63.
(5) The light is incident on the light receiving surface of the light receiving element 51 and transmitted to an external storage means (not shown) as an electronic signal.

In the weak light measuring device according to the present invention, it is preferable that the inside of an external container such as a chamber is cooled to a temperature of 10 ° C. or less. In this case, background light due to thermal radiation can be suppressed to such an extent that highly accurate measurement is possible. The cooling means is preferably a means using liquid nitrogen or its vapor from the viewpoint of simplicity and the like, but a cooling means utilizing adiabatic compression or Peltier effect can also be used.
It is also preferable to replace the inside of the outer container with nitrogen gas or the like in advance to prevent the occurrence of dew condensation.

The sample container preferably has heat insulation and airtightness. In this case, the sample peripheral portion and the outside of the sample container are insulated from each other and can be maintained at different temperatures. As the emission part of the sample container, one having a function as a cut filter that blocks light on the short wavelength side may be used. Although it is preferable to use a PMT as the light receiving element, another light receiving element having sensitivity to a predetermined wavelength may be used. In order to split the light to be detected into only a predetermined wavelength, the optical system preferably includes a spectral unit such as an optical filter. The arrangement of these optical system members is not limited to the arrangement as in the present embodiment. For example, it is preferable to arrange an optical filter near the light receiving element from the viewpoint of cooling characteristics and the like.

When the object to be measured is a sample collected from a living body or the like, it is preferable that at least the temperature around the sample in the sample container is in the range of 10 ° C. to 40 ° C. from the viewpoint of maintaining the function of the sample. The temperature holding means in the sample container is not limited to a constant temperature pump, and other means corresponding to a desired temperature range can be used.

FIG. 2 is a conceptual diagram of a second embodiment of the weak light measuring device according to the present invention as viewed from a cross section. In the weak light measurement device 12 according to the present embodiment, the following additions or substitutions (a) to (c) are performed on the device 11 according to the first embodiment.

(A) Instead of the sample container 31, another sample container 43 is used. This sample container 43 is a box-shaped container having a double structure having the exit window 33, and the intermediate layer is vacuum. By thus forming the sample container in a double structure, the heat insulation between the internal constant temperature part and the external low temperature part is further improved. The double layered intermediate layer may be filled with a heat insulating agent. (B) A temperature sensor 77 for measuring the temperature around the biological sample S and sending a signal to the constant temperature pump unit 71 is provided. By adding such a temperature sensor,
The temperature around the sample can be ascertained and the temperature can be accurately maintained. (C) The cooling container 53 is installed in the chamber 21 so as to include the light receiving element 51 therein. The cooling container 53 includes an inlet 55 for introducing a coolant, and an outlet 57 for extracting the coolant. The inlet 55 is connected to the inlet 23 via the coolant channel 27. You. In this case, the coolant flowing from the inlet 23 firstly flows through the coolant channel 27 and the inlet 55 to the cooling container 5.
Circulate into 3. Subsequently, it flows out of the cooling container 53 through the outlet 57 and circulates throughout the chamber 21.
When the coolant follows such a circulation path, the light-receiving element is cooled to a temperature equal to or lower than the temperature outside the cooling container 53, so that dew condensation on the light-receiving surface of the light-receiving element can be prevented. Further, cooling means for the light receiving element can be separately added.

FIG. 3 is a conceptual view of a third embodiment of the weak light measuring device according to the present invention as viewed from a cross section. In the weak light measurement device 13 according to the present embodiment, the following addition (d) is performed to the device 12 according to the second embodiment.

(D) A metal layer having a high thermal conductivity is formed on the outer surface of the sample container 43 excluding the exit window 33 and on the outer surfaces of the heat insulating channels 39 and 41 in the chamber 21 (in this embodiment, Is coated with aluminum foil) 45. In this case, the surfaces covered with the metal layers 45 are effectively cooled, so that heat radiation from these surfaces can be suppressed.

FIG. 4 is a conceptual view of a fourth embodiment of the weak light measuring device according to the present invention as viewed from a cross section. In the weak light measurement device 14 according to the present embodiment, the following additions or substitutions (e) and (f) are performed on the device 13 according to the third embodiment.

(E) Instead of the box-shaped sample container 43, an integrating sphere-shaped sample container 47 is used.
Are connected to the heat insulating channels 39 and 41. As in the third embodiment, a metal layer 45 having a high thermal conductivity is coated on the outer surface of the sample container 47 except for a portion from which light is emitted. In this case, light emitted from the biological sample S is efficiently emitted due to reflection on the inner surface of the integrating sphere type sample container 47.
(F) An electromagnetic shutter 59 is provided in a portion of the cooling container 53 where light enters. In this case, it is possible to prevent excessive light from being incident on the light receiving element 51 at the time of sample exchange or the like.

FIG. 5 is a conceptual view of a fifth embodiment of the weak light measuring device according to the present invention as viewed from a cross section. In the weak light measurement device 15 according to the present embodiment, the following additions (g) and (h) are made to the device 14 according to the fourth embodiment.

(G) An external calculation means 81 capable of storing and calculating an electronic signal is provided outside the chamber 21 and connected to the light receiving element 51 via a conductive cord 83. (H) An inlet 85 for introducing an activator into the sample container 47 is provided in the heat-insulating channel 39 outside the chamber 21.

In this embodiment, first, the sample container 4
The luminescence from the sample before generation of the substance to be measured introduced into 7 (that is, the biological sample before singlet oxygen is generated) is measured, and the measurement result is stored in the external calculation means 81 via the conductive code 83. . Subsequently, an activator such as an enzyme is introduced from the inlet 85 to generate singlet oxygen in the biological sample. After that, the luminescence from this sample is measured, the measurement result is stored in the external calculation means 81, and the luminescence from singlet oxygen is calculated by taking the difference between the measurement results. in this case,
Since the same sample and the same detection system are used, errors unlike the conventional apparatus are less likely to occur.

The weak light measuring device according to the present invention is not limited to the above embodiment, and various modifications such as adding only (b) and (f) to the first embodiment are possible. Therefore, a suitable form can be taken in accordance with the measurement conditions and the like.

[0033]

According to the weak light measuring device of the present invention,
Since the background light due to the heat radiation of the apparatus or the like is almost completely removed, the S / N ratio is improved, and the weak light can be measured with high accuracy. Further, weak light from singlet oxygen in a biological sample or the like can be suitably measured.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of a first embodiment of a weak light measuring device according to the present invention as viewed from a cross section.

FIG. 2 is a conceptual diagram of a second embodiment of the weak light measuring device according to the present invention as viewed from a cross section.

FIG. 3 is a conceptual diagram of a third embodiment of the weak light measuring device according to the present invention as viewed from a cross section.

FIG. 4 is a conceptual diagram showing a fourth embodiment of a weak light measuring device according to the present invention as viewed from a cross section.

FIG. 5 is a conceptual diagram of a fifth embodiment of a weak light measuring device according to the present invention as viewed from a cross section.

[Explanation of symbols]

11: first weak light measuring device, 12: second weak light measuring device, 13: third weak light measuring device, 14: fourth weak light measuring device, 15: fifth weak light measuring device, 21: chamber, 23: inlet, 25: outlet, 27: coolant channel, 31: sample container, 33: exit window, 35: inlet, 3
7 ... Outlet, 39 ... Insulated channel, 41 ... Insulated channel, 43 ...
Double sample container, 45: metal layer, 47: integrating sphere sample container, 51: light receiving element, 53: cooling container, 55: inlet, 57: outlet, 61: optical system, 63: condensing Lens, 65 optical filter, 71 constant temperature pump, 73 inlet, 75 outlet, 77 temperature sensor, 81 external calculation means, 83 conductive code, 85 inlet, S biological sample

Continuing from the front page (72) Inventor Teruo Hiruma 1126-1, Nomachi, Ichinomachi, Hamamatsu City, Shizuoka Prefecture Inside (72) Inventor Hirofumi Suga 1126-1, Nomachi, Ichinomachi, Hamamatsu City, Shizuoka Prefecture Hamamatsu Photonics Corporation F term (reference) 2G054 AA06 CA08 CA21 CD03 EA02 FA36 FA37 2G057 AA04 AA20 AC10 BA01 EA06 EA08 2G059 AA10 BB12 DD13 DD15 DD17 DD18 EE06 HH06 JJ02 JJ11 KK02 KK09

Claims (10)

[Claims] 1. A sample container having an emission part for emitting light emitted from a sample housed therein, an optical system including a condensing means for condensing at least light emitted from the emission part, and the optical system A light-receiving element that receives the light collected by the light-emitting device, an insulating container having heat insulation, airtightness, and light-shielding properties, an external container including the sample container, the optical system, and the light-receiving element, A weak light measurement device comprising: a cooling unit that cools to a first temperature; and a temperature holding unit that holds at least a temperature of a peripheral portion of the sample inside the sample container at a second temperature. 2. The weak light measuring device according to claim 1, wherein the first temperature is a temperature of 10 ° C. or less. 3. The weak light measuring device according to claim 1, further comprising a cooling unit configured to cool the light receiving element to a temperature equal to or lower than the first temperature. 4. The weak light measuring device according to claim 1, wherein said cooling means is means using liquid nitrogen or vapor thereof. 5. The device according to claim 1, wherein the sample container is a container having heat insulation and airtightness. 6. The device according to claim 1, wherein the sample container is a container having a double structure. 7. The weak light measuring device according to claim 1, wherein a metal is coated on an outer surface of the sample container except for the emission part. 8. The weak light measuring device according to claim 1, wherein the sample container is a spherical container. 9. The apparatus according to claim 1, wherein the second temperature is in a range of 10 ° C. to 40 ° C. 10. The weak light measuring device according to claim 1, further comprising a temperature sensor for sensing a temperature of at least a peripheral portion of the sample inside the sample container.