JPH0456259B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a measurement kit for autoradiography.

After administering a radioactively labeled substance to an organism, the organism or a part of its tissue is used as a sample, and this sample is overlapped with a radiation film such as a high-sensitivity X-ray film for a certain period of time. The film may be exposed to light (or
Autoradiography (also referred to as radioautography), which involves exposing a sample to light and obtaining positional information of a radiolabeled substance in the sample from the photosensitive site, has been known for some time. This autoradiography is used, for example, to study in detail the metabolism, absorption, and excretion routes and conditions of administered substances in living organisms. Such autoradiography is described, for example, in the following literature.

Biochemistry Experiment Course 6 Tracer Experiment Method (1)
pp. 271-289, "8. Autoradiography" Toru Sueyoshi, Akiyo Shigematsu (1977, published by Tokyo Kagaku Dojin Co., Ltd.) In recent years, autoradiography has been used to analyze the tissues of living organisms that have been given radioactive labels. And/or it is also effectively used to obtain positional information of radiolabeled substances in support media containing substances derived from living organisms.

For example, a radioactive label is attached to a biologically derived polymeric substance such as a protein or a nucleic acid, and the radiolabeled polymeric substance, its derivative, or its decomposition product is subjected to separation and development operations such as gel electrophoresis to form a gel. By separating and developing the gel-like support medium and a high-sensitivity X-ray film for a certain period of time, the film is exposed to light, and the positional information of the radiolabeled substance in the gel obtained from the exposed area is obtained. Based on this, methods for separating and identifying the polymeric substances, or evaluating the molecular weight and characteristics of the polymeric substances have also been developed and are in actual use.

Such autoradiography is described, for example, in the following literature:

“ELECTROPHORESIS OF PROTEINS”
IN POLYACRYLAMIDE AND STARCH
GELS”, AHGordon (North-Holland
Publishing Company, Amsterdam 1969): Japanese translation ``Gel Electrophoresis,'' published by Tokyo Kagaku Dojin 1974. Particularly in recent years, autoradiography has also been effectively used to determine the base sequence of nucleic acids such as DNA. It has become an extremely useful tool for determining the structure of polymeric substances derived from living organisms.

The method for determining the base sequence of DNA using this autoradiography is as follows.
Maxam-Gilbert method,
and Sanger Coulson
Coulson) law is known. These methods are
DNA has a double helical structure consisting of two chain molecules, and each of the two chain molecules contains four types of bases: adenine (A), guanine (G),
It is composed of structural units containing the bases cytosine (C) and thymine (T), and the two chain molecules are cross-linked by hydrogen bonds between these four types of bases. Moreover, hydrogen bonds between each structural unit are realized only in two types of combinations: G-C and A-T.
This method cleverly utilizes the characteristic structure of DNA to determine its base sequence.

For example, the Maxam-Gilbert method is carried out by the operations described below.

By bonding a group containing a radioactive isotope of phosphorus (P) to one end of a chain molecule of DNA or a DNA degradation product whose base sequence is to be determined, the target substance can be labeled as a radiolabeled substance. After that, the bonds between each base of the chain molecule are cleaved base-specifically using chemical means. Next, the DNA obtained by this operation or a mixture of a large number of base-specific cleavage products of the DNA degradation product is separated and developed on a support medium by gel electrophoresis, and a large number of base-specific cleavage products are separated into bands. can be formed to obtain a separated unfolded column (which cannot be seen visually). When this support medium and a high-sensitivity X-ray film are overlapped for a long time at low temperature, the part of the X-ray film facing the position where the base-specific cleavage product containing the radioactive isotope in the molecule is present. It is exposed to light and forms a latent image. By developing the X-ray film on which the latent image has been formed in this way, an autoradiograph consisting of a large number of bands appears as a visible image on the X-ray film. Then, from this visualized autoradiograph and the base-specific cutting means, it is possible to sequentially determine the bases in a certain positional relationship from the end of the chain molecule to which the radioactive isotope is bound. It is possible to determine the sequence of all the bases of a target object.

The Maxam-Gilbert method summarized above is described in detail in the following document.

METHODS IN ENZYMOLOGY, VOL.65,
PART (ACADEMIC PRESS, NEW
YORK LONDON TRONTO SYDNEY SAN
FRANCISICO, 1980) The Sanger-Coulson method also focuses on the characteristic structure of DNA and uses DNA synthase, gel electrophoresis, and autoradiography to analyze DNA.
A brief description of the characteristics and operations of the Sanger-Krewson method and the Maxam-Gilbert method can be found in the following documents.

“Reading genetic information in its original language: An unexpected DNA sequence analysis method” Kinichiro Miura, Gendai Kagaku, September 1977 issue, pp. 46-54 (published by Tokyo Kagaku Doujin Co., Ltd.) As mentioned above, Autoradiography is the separation and development of a sample consisting of a mixture of substances derived from living organisms with radioactive labels using a support medium (for example, a support medium for electrophoretic separation or a support medium for thin layer chromatography). Later, the one-dimensional or two-dimensional positional information of each substance separated and developed on the support medium is detected and measured using the radioactivity of the substance, thereby performing separation and identification of the substances. It is effectively used for this purpose. Therefore, by using this type of autoradiography, for example, it is possible to efficiently determine the structure of biopolymers, and in recent years, this type of autoradiography has become widely used. ing.

However, there are several problems when actually utilizing such useful autoradiography.

The first is to visualize an autoradiograph of a radiolabeled substance separated and developed on a support medium by overlapping the support medium and a radiation film such as a high-sensitivity X-ray film for a certain period of time. The operation of exposing the film to light is complicated and requires a long time.
That is, in conventional autoradiography, the above exposure operation is performed at low temperatures (for example, around 0°C,
In the case of exposure of a gel-like support medium in the determination of base sequences of nucleic acids, the exposure is carried out at a temperature of -70 to -90°C for a long period of time (for example, several days). This is because ordinary radiolabeled substances that are measured by autoradiography generally do not have high radioactivity, so exposure must be long in order to obtain sufficient photosensitivity.
For example, if a support medium and a radiation film are kept superimposed for a long time at a relatively high temperature such as room temperature, the silver salt, which is the photosensitive component of the radiation film, will be chemically fogged by various substances in the support medium. For this reason, it is difficult to obtain a highly accurate photosensitive image on the film, and therefore, in order to reduce such chemical fog, it is necessary to carry out the exposure operation at a low temperature. It may be possible to further increase the sensitivity of radiographic film to alleviate such harsh exposure conditions, but conventional radiographic film used for autoradiography is already highly sensitive. Considering the sharpness of the images obtained, it is difficult to dramatically increase the sensitivity of radiation films.

In addition, the silver salt of the photosensitive component of radiation film has the disadvantage that it is easily affected not only by chemical stimuli but also by physical stimuli, which also makes autoradiography difficult to operate and reduces its accuracy. becomes. In other words, in autoradiography, it is generally necessary to perform the exposure operation with the radiation film in contact with a support medium, so operations such as moving and installing the radiation film are often performed with the radiation film in a bare state. . Therefore, during such work, the chances of the radiation film coming into contact with the operator's hands or the equipment increase, and the radiation film is subject to the physical fog phenomenon due to the physical pressure caused by such contact. There is a tendency for this to occur, and this point also causes a decrease in the accuracy of autoradiography. In order to avoid such physical fogging of the radiographic film, a high degree of skill and care is required in handling the film, which results in further complicated autoradiography operations.

Furthermore, since conventional autoradiography involves long exposure operations as described above, the natural radioactivity contained in the sample in addition to the radiolabeled substance is also involved in the exposure of the radiographic film, and the resulting radioactivity is There is a problem in that the accuracy of the positional information of the labeling substance is reduced. In order to eliminate such interference due to natural radioactivity, attempts have been made, for example, to conduct parallel experiments using control samples and to optimize the exposure time. The disadvantage is that the entire operation becomes complicated due to the necessity of preliminary experiments to determine the exposure time.

As a result of intensive research aimed at solving the above-mentioned problems associated with conventional autoradiography, the inventors of the present invention have discovered that radiation film can be used as a photosensitive material to be used in combination with a support medium for separation and development. Instead, by using a stimulable phosphor sheet having a phosphor layer made of stimulable phosphor and attaching the above-mentioned support medium to this stimulable phosphor sheet, the above problems or drawbacks can be solved or The present invention has been achieved based on the discovery that the reduction in

That is, when a stimulable phosphor sheet having a phosphor layer made of a stimulable phosphor is used as a photosensitive material used to obtain positional information of a radiolabeled substance on a support medium for separation and development, the exposure time is Not only is it possible to significantly shorten the time required for exposure, but it is also possible to perform exposure without reducing the accuracy of the obtained positional information of the radiolabeled substance, even under relatively high temperature conditions such as at or near ambient temperature. It turned out that it can be done. This point significantly simplifies the exposure operation in autoradiography, which has conventionally been carried out under cooling. Furthermore, by realizing a significant reduction in exposure time, the entire autoradiography operation can be performed efficiently in a short time, which is also very advantageous in practical terms.

Furthermore, by using the above-mentioned stimulable phosphor sheet as a photosensitive material for autoradiography, chemical fog and physical fog, which have been a major problem when using conventional radiation films, are virtually eliminated. It has a very advantageous effect on improving the accuracy and workability of autoradiography.

Furthermore, when a stimulable phosphor sheet is used as a photosensitive material, there is no need to image it in order to obtain positional information of the radiolabeled substance transferred from the sample to the stimulable phosphor sheet; By scanning the phosphor sheet with electromagnetic waves such as a laser, the above positional information can be read out, and the positional information can be converted into any form such as an image, symbol, numerical value, or a combination thereof. . Furthermore, by further processing the above position information using electrical means, it is also possible to obtain the necessary information in various desired forms.

Furthermore, a gel-like support medium, which is a typical example of a support medium for separation and deployment, is generally used in the form attached to a medium (supporting aid) such as a glass plate or a plastic sheet. In the present invention, by integrating the support medium for separation and development and the stimulable phosphor sheet, the stimulable phosphor sheet can function as a substrate in the separation and development operation of the sample. . Further, the present invention does not require the work of overlapping the support medium for separation and development and the photosensitive material, which has been performed in the exposure operation of conventional autoradiography. In conventional autoradiography that uses a radiation film as a photosensitive material, it is actually impossible to integrate the photosensitive material and the support medium for separation and development in advance as in the present invention. In this respect as well, the present invention can contribute to simplifying the operation of autoradiography and shortening the required time.

Therefore, the present invention provides a stimulable phosphor sheet having a phosphor layer made of a stimulable phosphor, and a support medium provided on the sheet for separating and developing a substance derived from a radioactively labeled organism. The present invention provides an autoradiography measurement kit including:

The present invention will now be described in detail with reference to the accompanying drawings.

Typical embodiments of the kit for autoradiography measurement of the present invention include the following embodiments.

(1) Autoradiography measurement kit consisting of a stimulable phosphor sheet and a support medium for separation and development provided on this sheet (2) A stimulable phosphor sheet and a support medium for separation and development provided on this sheet and (3) a stimulable phosphor sheet provided with a hydrophilicity-imparting layer, and a stimulable phosphor sheet provided on the hydrophilicity-imparting layer. A measurement kit for autoradiography consisting of a support medium for separation and development.

(4) A measurement kit for autoradiography consisting of a stimulable phosphor sheet provided with a hydrophilicity-imparting layer, a support medium for separation and development provided on the hydrophilicity-imparting layer, and a coating on the surface of this support medium. .

In the autoradiography measurement kits 2) and 4), the surface of the support medium for separation and development may also be coated on the surface and side surfaces of the support medium that are not in contact with the sheet. In addition, in the autoradiography measurement kits 3) and 4), the hydrophilicity-imparting layer refers to a sheet that has been made hydrophilic with respect to the support medium for separation and development by activating the surface of the stimulable phosphor sheet. shall include the surface.

However, the above four types of embodiments are examples of typical embodiments, and the autoradiography measurement kit of the present invention is not limited to the above four types of embodiments.

FIG. 1 is a longitudinal cross-sectional view showing an embodiment of the four types of autoradiography measurement kits described above.

FIG. 1-a shows a measurement kit consisting of a stimulable phosphor sheet 1a and a support medium 2a for separation and development provided thereon.

FIG. 1-b shows a measurement kit consisting of a stimulable phosphor sheet 1b, a support medium 2b for separation and development provided thereon, and a covering 3b provided thereon.

FIG. 1-c consists of a stimulable phosphor sheet 1c, a hydrophilicity imparting layer 4c provided thereon, and a support medium 2c for separation and development provided thereon.

FIG. 1-d shows a stimulable phosphor sheet 1d, a hydrophilicity imparting layer 4d provided thereon, a support medium 2d for separation and development provided thereon, and a coating 3d further provided thereon. Consisting of

The stimulable phosphor sheet used as one component in the autoradiography measuring kit of the present invention is also called a radiation image exchange panel, and examples thereof include, for example, Japanese Patent Laid-Open No. 55-12145.
The general structure is already known.

In other words, the stimulable phosphor sheet absorbs the radiation energy transmitted through the subject or the radiation energy emitted from the subject into the stimulable phosphor of the panel, and then exposes the stimulable phosphor to visible light and infrared rays. By exciting the stimulable phosphor in a time-series manner using electromagnetic waves (excitation light), the radiation energy stored in the stimulable phosphor is released as fluorescence, and this fluorescence is read photoelectrically to obtain an electrical signal. This electrical signal is reproduced as a visible image on a recording material such as a photosensitive film or a display device such as a CRT, or is expressed as numerical or symbolic position information.

The stimulable phosphor sheet preferably used in the autoradiography measurement kit of the present invention will be briefly described below.

The basic structure of the above stimulable phosphor sheet is as follows:
It consists of a support and a phosphor layer provided on one side of the support. However, the surface of this phosphor layer opposite to the support (the surface not facing the support) is generally provided with a transparent protective film, which protects the phosphor layer from chemical or physical alterations. Protects from strong impacts.

The phosphor layer generally consists of a stimulable phosphor and a binder that contains and supports the stimulable phosphor in a dispersed state. After absorbing radiation, the stimulable phosphor absorbs radiation such as visible light and infrared rays. It has the property of emitting light (stimulated luminescence) when irradiated with electromagnetic waves (excitation light). Therefore, for example, radiation emitted from an object such as a sample containing a radiolabeled substance is absorbed by the phosphor layer of the stimulable phosphor sheet in proportion to the amount of radiation, and the radiation is absorbed by the phosphor layer of the stimulable phosphor sheet. A radiation image of the subject is formed as an image of accumulated radiation energy. This accumulated image can be emitted as stimulated luminescence (fluorescence) by exciting it with electromagnetic waves (excitation light) such as visible light and infrared rays, and the stimulated luminescence can be read photoelectrically and converted into an electrical signal. By doing so,
It becomes possible to convert the accumulated radiation energy image into a visible image, or into numerical values, symbols, etc. indicating the positional information of the radioactive (labeled) substance.

The support for the stimulable phosphor sheet used in the present invention can be arbitrarily selected from various materials used as supports for intensifying screens in conventional radiography. Examples of such materials include films of plastic materials such as cellulose acetate, polyester, polyethylene terephthalate, polyamide, polyimide, triacetate, polycarbonate, metal sheets such as aluminum foil, aluminum alloy foil, ordinary paper,
Examples include baryta paper, resin-coated paper, pigment paper containing pigments such as titanium dioxide, and paper sized with polyvinyl alcohol. However, when considering the characteristics and handling of the stimulable phosphor sheet as an information recording material, a particularly preferred material for the support in the present invention is plastic film. This plastic film may be kneaded with a light-absorbing substance such as carbon black, or may be kneaded with a light-reflecting substance such as titanium dioxide. The former is a support suitable for a high sharpness type stimulable phosphor sheet, and the latter is a support suitable for a high sensitivity type stimulable phosphor sheet.

In known stimulable phosphor sheets, in order to strengthen the bond between the support and the phosphor layer, or to improve the sensitivity or image quality of the stimulable phosphor sheet, the surface of the support on the side where the phosphor layer is provided is A polymeric substance such as gelatin is coated on the surface to form an adhesion-imparting layer, or a light-reflecting layer made of a light-reflecting substance such as titanium dioxide or a light-absorbing layer made of a light-absorbing substance such as carbon black is provided. is also being carried out. The support used in the present invention can also be provided with these various layers, and their configurations can be arbitrarily selected depending on the desired purpose, use, etc. of the stimulable phosphor sheet.

Furthermore, as disclosed in Japanese Patent Application No. 57-82431 filed by the present applicant, in order to improve the sharpness of the resulting image, the surface of the support on the phosphor layer side (the phosphor layer side of the support) (If the surface of the layer is provided with an adhesion-imparting layer, a light-reflecting layer, a light-absorbing layer, or a metal foil, this means the surface thereof)
The surface may have unevenness formed thereon.

A phosphor layer is formed on the support as described above. The phosphor layer is generally a layer made of a binder containing and supporting particulate stimulable phosphor in a dispersed state.

As mentioned above, a stimulable phosphor is a phosphor that exhibits stimulated luminescence when irradiated with radiation and then with excitation light, but from a practical point of view, it has a wavelength of 400~
300-500nm with excitation light in the 800nm range
It is desirable that the phosphor exhibits stimulated luminescence in the wavelength range of . The stimulable phosphor used in the stimulable phosphor sheet used in the present invention is preferably a divalent europium-activated alkaline earth metal fluorohalide phosphor, but is not limited thereto. It's not a thing.

Examples of stimulable phosphors used in the stimulable phosphor sheet used in the present invention include those described in U.S. Pat. No. 3,859,527.
Phosphors expressed by composition formulas such as SrS:Ce, Sm, SrS:Eu, Sm, ThO ₂ :Er, and La ₂ O ₂ S:Eu, Sm, as described in JP-A-55-12142.
ZnS: Cu, Pb, BaO・xAl ₂ O ₃ : Eu [however, 0.8
≦x≦10], and M〓O・xSiO ₂ :A [however,
M〓 is Mg, Ca, Sr, Zn, Cd, or Ba,
A is Ce, Tb, Eu, Tm, Pb, Tl, Bi, or
A phosphor represented by a composition formula such as Mn, and x is 0.5≦x≦2.5] is described in JP-A-55-12143 (Ba _1-xy , Mg _x , Ca _y ) FX: aEu ²⁺ [However, X
is at least one of Cl and Br,
A phosphor represented by the composition formula: x and y are 0<x+y≦0.6 and xy≠0, and a is 10 ^-6 ≦a≦5×10 ^-2 JP-A-12144-1987 stated in the issue
LnOX: xA [However, Ln is La, Y, Gd, and
At least one of Lu, X is at least one of Cl and Br, A is at least one of Ce and Tb, and x is 0<x<0.1
A phosphor _represented by the composition formula of (Ba _1-x , M〓
At least one of Ca, Sr, Zn, and Cd, X is at least one of Cl, Br, and I, A is Eu, Tb, Ce, Tm, Dy, Pr, Ho,
At least one of Nd, Yb, and Er, x is 0≦x≦0.6, and y is 0≦y≦0.2] JP-A-55-160078 M listed in the official bulletin
FX・xA: yLn [However, M〓 is Ba, Ca, Sr,
At least one of Mg, Zn, and Cd, A
is BeO, MgO, CaO, SrO, BaO, ZnO, _Al2
O ₃ , Y ₂ O ₃ , La ₂ O ₃ , In ₂ O ₃ , SiO ₂ , TlO ₂ , ZrO ₂ ,
At least one of GeO ₂ , SnO ₂ , Nb ₂ O ₅ , Ta ₂ O ₅ , and ThO ₂ , Ln is Eu, Tb, Ce,
At least one of Tm, Dy, Pr, Ho, Nd, Yb, Er, Sm, and Gd, X is at least one of Cl, Br, and I, and x and y are each 5×10 ^-5 ≦x≦0.5 and 0≦y
≦0.2], which is described in Japanese Patent Application Laid-open No. 116777/1982 (Ba _1-x , M〓 _x ) F ₂・aBaX ₂ : yEu, zA
M〓 is beryllium, magnesium, calcium,
at least one of strontium, zinc, and cadmium; X is at least one of chlorine, bromine, and iodine; A is at least one of zirconium and scandium;
a, x, y, and z are each 0.5≦a≦1.25,
0≦x≦1, 10 ^-6 ≦y≦2×10 ^-1 , and 0<z
≦10 ^-2 ], described in Japanese Patent Application Laid-open No. 57-23673, (Ba _1-x , M〓 _x ) F ₂・aBaX ₂ :yEu, zB ,
M〓 is beryllium, magnesium, calcium,
at least one of strontium, zinc, and cadmium;
10 ^-6 ≦y≦2×10 ^-1 and 0<z≦2×10 ^-1 ] A phosphor is described in JP-A-57-23675 (Ba _{1 -x} , M〓 _x )F ₂・aBaX ₂ :yEu, zA [however,
M〓 is beryllium, magnesium, calcium,
at least one of strontium, zinc, and cadmium; X is at least one of chlorine, bromine, and iodine; A is at least one of arsenic and silicon; a, x, y, and z are each 0.5 ≦a≦1.25, 0≦x≦1, 10 ^-6
≦y≦2×10 ^-1 , and 0<z≦5×10 ^-1 ], M as described in Japanese Patent Application No. 167498/1983 filed by the present applicant 〓OX: xCe [However, M〓 is Pr,
Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm,
is at least one trivalent metal selected from the group consisting of Yb, and Bi, X is one or both of Cl and Br, and x is 0<x<0.1]. The represented phosphor is Ba _1-x M _x/2 L _x/2 FX:yEu ²⁺ [However,
M represents at least one alkali metal selected from the group consisting of Li, Na, K, Rb, and Cs; L represents Sc, Y, La, Ce, Pr, Nd, Pm,
Sm, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu,
represents at least one trivalent metal selected from the group consisting of Al, Ga, In, and Tl; X is Cl,
represents at least one halogen selected from the group consisting of Br, and I; and x is 10 ^-2 ≦
x≦0.5, y is 0<y≦0.1] BaFX xA:yEu ²⁺ [However, ,X is
is at least one halogen selected from the group consisting of Cl, Br, and I; A is a fired product of a tetrafluoroboric acid compound; and x is
10 ^-6 ≦x≦0.1, y is 0<y≦0.1] BaFX xA: yEu described in Japanese Patent Application No. 158048/1983 filed by the present applicant ²⁺ [However, X is
at least one halogen selected from the group consisting of Cl, Br, and I; A is a hexafluoro compound consisting of a monovalent or divalent metal salt of hexafluorosilicic acid, hexafluorotitanic acid, and hexafluorozirconic acid; and x is 10 ^-6 ≦x≦0.1, and y is 0<y≦0.1. BaFX xNaX′: aEu ²⁺ described in Application No. 166320/1989 [However,
X and X′ are each at least one of Cl, Br, and I, and x and a are 0<x≦2 and 0<a≦0.2, respectively]; ^M〓FX . is a kind of alkaline earth metal; X and X' are Cl, Br, and I, respectively.
at least one halogen selected from the group consisting of; A is at least one transition metal selected from V, Cr, Mn, Fe, Co, and Ni; and x is 0<x≦2, y is 0<y≦
0.2, and z is 0<z≦10 ^-2 ], M〓FX・aM〓X′ described in the specification of Japanese Patent Application No. 184455/1983 filed by the present applicant.・bM′〓X″ ₂・cM〓
X route 3 xA: yEu ²⁺ [However, M〓 is Ba, Sr,
and at least one alkaline earth metal selected from the group consisting of Ca; M〓 is Li, Na,
is at least one kind of alkali metal selected from the group consisting of K, Rb, and Cs; M′〓 is at least one kind of divalent metal selected from the group consisting of Be and Mg; M〓 is Al, Ga, In ,and
at least one trivalent metal selected from the group consisting of Tl; A is a metal oxide; X is Cl;
Br, and at least one halogen selected from the group consisting of I;
is at least one halogen selected from the group consisting of F, Cl, Br, and I; and
a is 0≦x≦2, b is 0≦b≦10 ^-2 , c is 0≦c
≦10 ^-2 and a+b+c≧10 ^-6 ; X is 0<
Examples include a phosphor represented by the composition formula: x≦0.5, y is 0<y≦0.2.

However, the stimulable phosphor used in the present invention is not limited to the above-mentioned phosphors, but any phosphor that exhibits stimulated luminescence when irradiated with radiation and then irradiated with excitation light. It may be.

Examples of binders for the phosphor layer include proteins such as gelatin, polysaccharides such as dextran, or natural polymeric substances such as gum arabic; and polyvinyl butyral, polyvinyl acetate, nitrocellulose, ethylcellulose, chloride Examples of binders include synthetic polymeric substances such as vinylidene/vinyl chloride copolymer, polymethyl tacrylate, vinyl chloride/vinyl acetate copolymer, polyurethane, cellulose acetate butyrate, polyvinyl alcohol, linear polyester, etc. . Particularly preferred among such binders are nitrocellulose, linear polyesters, and mixtures of nitrocellulose and linear polyesters.

The phosphor layer can be formed on the support, for example, by the following method.

First, add the above-mentioned stimulable phosphor particles and a binder to a suitable solvent (e.g., lower alcohol, chlorine atom-containing hydrocarbon, ketone, ester, ether), mix thoroughly, and add the binder solution. A coating solution in which phosphor particles are uniformly dispersed is prepared.

The mixing ratio of the binder and the stimulable phosphor particles in the coating solution varies depending on the characteristics of the desired stimulable phosphor sheet, the type of phosphor particles, etc.
Generally, the mixing ratio of binder and phosphor particles is 1:
It is selected from the range of 1 to 1:100 (weight ratio), and particularly preferably selected from the range of 1:8 to 1:40 (weight ratio).

Note that the coating liquid contains a dispersant for improving the dispersibility of the phosphor particles in the coating liquid, and
Various additives such as a plasticizer may be mixed in order to improve the bonding force between the binder and the phosphor particles in the phosphor layer after formation. Examples of dispersants used for such purposes include phthalic acid, stearic acid, caproic acid, lipophilic surfactants, and the like. Examples of plasticizers include phosphate esters such as triphenyl phosphate, tricresyl phosphate, and diphenyl phosphate; phthalate esters such as diethyl phthalate and dimethoxyethyl phthalate; ethyl phthalyl ethyl glycolate, butyl phthalyl glycolate, etc. and polyesters of polyethylene glycol and aliphatic dibasic acids, such as polyesters of triethylene glycol and adipic acid and polyesters of diethylene glycol and succinic acid.

The coating solution containing the phosphor particles and binder prepared as described above is then uniformly applied to the surface of the support to form a coating film of the coating solution. This coating operation can be carried out using conventional coating means such as a doctor blade, roll coater, knife coater, etc.

The formed coating film is then dried by gradually heating to complete the formation of the phosphor layer on the support. The thickness of the phosphor layer varies depending on the characteristics of the desired stimulable phosphor sheet, the type of phosphor particles, the mixing ratio of the binder and the phosphor particles, etc.
Usually it is 20 μm to 1 mm. However, the thickness of this layer is preferably 50 to 500 μm.

Note that the phosphor layer does not necessarily need to be formed by directly applying a coating liquid onto the support as described above; for example, it is possible to form the phosphor layer by separately applying the coating liquid onto a sheet such as a glass plate, metal plate, plastic sheet, etc. After the phosphor layer is formed by drying, it may be pressed onto the support, or the support and the phosphor layer may be joined by a method using an adhesive.

Preferably, a protective film is provided on the phosphor layer as described above. This protective film is made of, for example, transparent cellulose derivatives such as cellulose acetate and nitrocellulose; polymethyl methacrylate, polyvinyl butyral, polyvinyl formal, polycarbonate, polyvinyl acetate/vinyl acetate copolymer, polyethylene terephthalate, polyethylene, polyvinylidene chloride, polyamide, etc. It is made of a transparent synthetic polymer material. The thickness of the protective film is usually 0.1 to 100 μm, preferably 0.3 to 50 μm.

Next, the support medium, which is the other component of the autoradiography measurement kit of the present invention, that is, the support medium for separating and developing the radioactively labeled biological substance, is added to It is attached to the surface of the body sheet (the surface of the phosphor layer, or the surface of the protective film if a protective film is provided on the surface).

The support medium used in the present invention can be arbitrarily selected from various support media for separation and development that have been used or proposed for use in conventional autoradiography techniques. Examples of such support media for separation development include support media for electrophoretic separation in the form of gel-like support media, polymer moldings such as acetate membranes, or various support media such as filter paper, and thin films such as silica gel. Mention may be made of support media for layer chromatography. These support media for development and separation usually constitute the measurement kit of the present invention in a dry state, but if desired, they may be impregnated with a solvent for separation and development to constitute the kit. good.

Note that the support medium for separation and development is not limited to the support media exemplified above, but may be one that can be used for separation and development of samples in autoradiography technology and that can be attached to a stimulable phosphor sheet. Any support medium can be used.

It is preferable that the support medium for separation and development is applied onto the stimulable phosphor sheet at the same time as the support medium is formed. The formation of the support medium on the stimulable phosphor sheet can be carried out in accordance with the operation of forming the support medium on a common substrate (supporting aid) such as a glass plate or plastic film. For example, a solution (or suspension) is created by dissolving (or dispersing) the support medium raw materials in a suitable solvent.
After that, apply this solution to the surface of the stimulable phosphor sheet (the surface of the phosphor layer, or the surface of the protective film if a protective film is provided on that surface), and place a plastic frame on the sheet. The support medium can be formed, such as by pouring into it or by simply coating it. however,
The support medium can also be formed in advance on a common substrate such as a glass plate or plastic film and then attached to the stimulable phosphor sheet according to conventionally known techniques.

The solvent to be used can be arbitrarily selected depending on the purpose from various known solvents, pH-adjusted buffers, etc. in combination with the support medium raw materials. Such solvents are already well known and will not be specifically mentioned here.

In the autoradiography measuring kit of the present invention, the surface of the support medium produced as described above is covered with a plastic material or the like in order to protect and preserve the support medium for separation and development in a usable state. It may be coated. This coating may be applied only to the surface of the support medium, or may be applied to the surface and sides of the support medium to form a seal. The coating may also be provided with an opening for sample injection, and the opening may be provided at a location corresponding to the edge of the support medium or at an arbitrary position on the surface of the support medium. good.

The measurement kit for autoradiography in which the surface (and/or the side surface of the support medium, if desired) is coated as described above may remain coated during autoradiography measurement, or Used in either uncoated or uncoated form.

In addition, in the autoradiography measurement kit of the present invention, in order to improve the adhesion between the stimulable phosphor sheet and the support medium for separation and development, the surface of the sheet on the side where the support medium is provided is made hydrophilic in advance. You can leave it there.

In the present invention, methods for making the surface of the stimulable phosphor sheet hydrophilic include, for example, a method of hydrophilizing the surface of the protective film, and a method of providing a hydrophilicity imparting layer on the surface of the phosphor layer (or protective film). be able to.

As a method for making the side surface of the protective film hydrophilic, for example, the following surface activation treatment can be used. Namely, chemical treatment using chemicals such as acid, alkali, and etching solution; physical treatment such as roughening treatment; electrical treatment such as corona discharge, high frequency discharge, glow discharge, and activated plasma; and light treatment such as ultraviolet rays and laser. Examples include treatment; flame treatment; ozone oxidation treatment.

In the latter method of providing a hydrophilicity-imparting layer on the surface of the phosphor layer (or protective film), examples of materials used for the hydrophilicity-imparting layer include natural polymer substances such as gelatin, starch, agarose, and cellulose, and derivatives thereof. Synthetic homopolymers such as polyvinyl alcohol, polyvinylpyrrolidone, polyacrylamide, polyhydroxyethyl methacrylate, and hydrophilic monomers and hydrophobic monomers having hydrophilic groups such as hydroxyl or carboxyl groups (e.g., ethylene, propylene, styrene, methacrylic acid) Hydrophilic synthetic polymer substances such as synthetic copolymers obtained by copolymerization with ethylenically unsaturated monomers such as esters, acrylate esters, vinyl chloride, vinylidene chloride, and dienes such as butadiene, isoprene, isobutylene, etc. Can be done.

The hydrophilicity-imparting layer can be applied onto the stimulable phosphor sheet by a known layer forming method, such as applying it to the sheet surface as a solution dissolved in water or other solvents, or as a latex-like dispersion. can. In addition, in order to improve the adhesion with the hydrophilicity-imparting layer, the sheet surface may be subjected to a hydrophilic treatment as described above. Further, the hydrophilicity imparting layer may be a single layer or may be laminated as a plurality of layers.

By imparting hydrophilicity to the surface of the stimulable phosphor sheet as described above, it is possible to increase the adhesion between the sheet and the support medium when the support medium for separation and development is an aqueous gel or the like. can.

When implementing a method of imparting hydrophilicity to the surface of a stimulable phosphor sheet, for example, U.S. Patent No.
No. 2698241, No. 2764520, No. 2864755, No.
No. 2864756, No. 2972534, No. 3057792, No.
No. 3071466, No. 3072483, No. 3143421, No.
No. 3145105, No. 3145242, No. 3360448, No.
It is possible to refer to the methods of hydrophilic treatment of plastic surfaces described in specifications such as No. 3376208, No. 3462335, No. 3475193, British Patent Nos. 788365, No. 804005, and No. 891469.

Next, an autoradiography operation using the measurement kit of the present invention will be explained.

The radiolabeled substance used in the autoradiography of the present invention can be obtained by allowing a sample to be measured to retain a radioactive element using an appropriate method.

The radioactive element used in the present invention is radiation (α
Any type of nuclide may be used as long as it emits rays, β-rays, γ-rays, neutron beams, X-rays, etc., but typical examples include 32P, 14C, 36S,
There are 3H, 125I, etc.

A sample to be subjected to separation and development in the present invention,
That is, examples of biologically derived substances having radioactive labels include polymeric substances such as proteins, nucleic acids, derivatives thereof, and decomposition products thereof. Methods for imparting radioactive labels to these substances are already well known. The biologically derived substances to be measured by the autoradiography measurement kit of the present invention are not limited to the above-mentioned polymeric substances.

In addition, separation and development methods using the various support media for separation and development as described above, such as methods of performing electrophoresis and forming separation and development arrays of samples on the support medium, are already well known. I won't touch on it in particular.

Next, the autoradiography measuring kit of the present invention, in which the sample has been separated and developed on the support medium, is irradiated with appropriate light, heat, etc. as necessary, so that the stimulable phosphor sheet is The radioactive energy accumulated in the molecule is released as fluorescence. In other words, the accumulation of radiation in the measurement kit is caused by the natural radioactivity contained in the sample, and by the radiation emitted from the moving radiolabeled substance during the separation and development of the radiolabeled sample on the support medium. When the stimulable phosphor sheet is exposed to light, a radiation energy accumulation image other than the object to be measured is formed on the stimulable phosphor sheet, which causes noise to the radiation energy accumulation image having the target autoradiograph. Therefore, if the influence of the noise is not negligible, it is desirable to eliminate the noise before forming a radiation energy accumulation image having the desired autoradiograph on the stimulable phosphor sheet.

Note that the above-mentioned noise erasing operation can be carried out with the support medium on which the radiochromatogram has been formed as it is, or after it has been subjected to any desired treatment such as drying treatment or fixation treatment of separated developed product. .

Next, the autoradiography measurement kit with the sample separated and developed on the attached support medium for separation and development is preferably left in a dark place or a dark box for a certain period of time to remove the stimulable phosphor sheet. At least a portion of the radiation emitted from the radiolabeled substance that has been exposed and separated and developed is absorbed by the stimulable phosphor sheet in the measurement kit. Through this operation, an autoradiograph of the radiolabeled substance separated and developed on the support medium is recorded on the stimulable phosphor sheet as an image of accumulated radiation energy.

In the above exposure operation, the exposure time varies depending on the strength of the radioactivity of the radiolabeled substance contained in the sample, the concentration and density of the substance, or the sensitivity of the stimulable phosphor sheet. However, when a stimulable phosphor sheet is used as a photosensitive material according to the present invention, the exposure time is significantly reduced compared to the exposure time required when using a conventional radiation film.

In addition, in the operation of reading out the positional information of the radiolabeled substance on the support medium that has been transferred and accumulated on the stimulable phosphor sheet from the support medium by exposure, the intensity and distribution of the energy stored in the phosphor sheet, Since the state of the obtained position information can be changed by performing various electrical processes depending on the desired information, there is no particular need to strictly control the exposure time during the exposure operation.

Although there is no particular restriction on the temperature at which the exposure operation is performed, autoradiography using the stimulable phosphor sheet of the present invention can be performed particularly at an environmental temperature of 10 to 35°C. However, the exposure operation may be performed at a low temperature (for example, around 5° C. or lower) as used in conventional autoradiography.

Next, the stimulable phosphor sheet is transferred and stored to read out the autoradiograph. This readout process can be performed with the support medium still attached to the stimulable phosphor sheet, or after separating only the stimulable phosphor sheet from the measurement kit; Preferably, only the sheet is subjected to the readout process. Depending on the purpose, the support medium can be easily removed from the stimulable phosphor sheet by, for example, peeling or scraping the support medium, washing it away using a solvent such as water, etc. .

In the present invention, an example of the reading device (or reading device) shown in FIG. A brief description will be given below with reference to the following.

Figure 2 shows a readout method for reading out one-dimensional or two-dimensional positional information of a radioactive label accumulated and recorded on a stimulable phosphor sheet (hereinafter sometimes abbreviated as phosphor sheet) 1. 1 shows a schematic diagram of an example of an apparatus.

In the reading device, the following reading operation is performed.

The laser light 3 generated from the laser light source 2 passes through the filter 4, whereby a portion of the wavelength range corresponding to the wavelength range of stimulated luminescence generated from the phosphor sheet 1 in response to excitation by the laser light 2 is cut out. Ru. The beam diameter of the laser beam 2 that has passed through the filter 4 is then precisely adjusted by a beam expander 5. Next, the laser beam is deflected by an optical deflector 6 such as a galvano mirror, reflected by a plane reflecting mirror 7, and then one-dimensionally deflected and incident on the phosphor sheet 1. Note that there is a space between the optical deflector 6 and the plane reflecting mirror 7.
An fθ lens 8 and the like are arranged so that when the polarized laser beam scans the phosphor sheet 1, a uniform beam speed is always maintained.

The laser light source 2 used here is selected so that the wavelength range of its laser light 4 does not overlap with the main wavelength range of stimulated luminescence emitted from the phosphor sheet 1.

The phosphor sheet 1 is transported in the direction of the arrow 9 under irradiation with the above-mentioned polarized laser light. Therefore, the entire surface of the phosphor sheet 1 is irradiated with the polarized laser light.

When the phosphor sheet 1 is irradiated with the laser light as described above, it exhibits stimulated luminescence with an amount of light proportional to the accumulated and recorded radiation energy, and this light enters the light guide sheet 10. This light guide sheet 10 has a linear incident surface, and the phosphor sheet 1
It is arranged close to the upper scanning line so as to face it, and its exit surface forms a ring and communicates with the light-receiving surface of a photodetector 11 such as a photodetector. The light guide sheet 10 is made by processing a transparent thermoplastic resin sheet such as acrylic synthetic resin, and allows light incident from the incident surface to be transmitted to the exit surface while being totally reflected inside. It is configured to Stimulated luminescence from the phosphor sheet 1 is guided through the light-guiding sheet 10 and reaches the exit surface, is emitted from the exit surface, and is received by the photodetector 11.

The preferred shape, material, etc. of the light-guiding sheet are disclosed in Japanese Patent Application Laid-open Nos. 55-87970 and 56-11397.

A filter is attached to the light-receiving surface of the photodetector 11, which transmits only light in the stimulated emission wavelength range and cuts out light in the excitation light (laser light) wavelength range.
It is designed to detect only stimulated luminescence. The stimulated luminescence detected by the photodetector 11 is converted into an electrical signal, and is amplified into an electrical signal at an appropriate level in the amplifier 13 whose sensitivity is set according to the amplification factor setting value a output from the control circuit 12. ,
The signal is input to the A/D converter 14. A/D converter 1
4 is converted into a digital signal by a scale factor suitable for the signal fluctuation width according to the recording scale factor setting value b output from the control circuit 12, and is input to the signal processing circuit 15. The signal processing circuit 14 performs signal processing based on the reproduced image processing condition setting value c also output from the control circuit 12 so as to obtain a visible image with appropriate density and contrast and excellent observation and interpretation performance. Then, if necessary, the data is transmitted to a recording device (not shown) via a storage means such as a magnetic tape.

Note that the amplification factor setting value a, the recording scale factor b, and the reproduction image processing condition setting value c output from the control circuit 12 are obtained by, for example, a preliminary reading operation (pre-reading operation) before the above-mentioned reading operation. According to the accumulated record information obtained by performing
In order to obtain an image with the most uniform density and contrast and excellent observation and interpretation performance,
If factors b and c can be set, or if the content of radioactive substances in a sample is known in advance, these factors can be determined according to the exposure time of the stimulable phosphor sheet for that sample. It can also be set.

Examples of recording devices include those that optically record by scanning a photosensitive material with a laser beam or the like;
There are recording devices based on various principles, such as those that display electronically on CRTs, etc., those that record radiation images displayed on CRTs, etc. on video printers, etc., and those that record on heat-sensitive recording materials using heat rays. Can be used.

However, the recording device is not limited to the one that visualizes the image as described above, but can also convert one-dimensional or two-dimensional positional information of the radioactive label in the sample into numbers, for example. can also be recorded as symbols.

Furthermore, as a method for reading out the positional information of the radiolabeled substance in the sample that has been transferred and accumulated on the stimulable phosphor sheet in the present invention, it is of course possible to use an appropriate method other than those exemplified above. .

In the present invention, "position information" of a radioactively labeled substance in a sample refers to various information centered on the position of a radioactively labeled substance or an aggregate thereof in a sample, such as an aggregate of radioactive substances present in a sample. Refers to various types of information obtained as one or any combination of information such as the location and shape of the body, the concentration and distribution of radioactive substances at that location, etc.

Next, an embodiment of autoradiography using the measurement kit of the present invention will be described, taking as an example the initial operation of the DNA base sequencing method using the aforementioned Maxam-Gilbert method.

The measurement kit used in the following examples was
It consists of a stimulable phosphor sheet prepared as described below, a support medium for electrophoresis and a coating provided above it.

Adding methyl ethyl ketone to a mixture of photostimulable europium-activated barium fluoride bromide phosphor (BaFBr:Eu) particles and linear polyester resin,
Further, nitrocellulose with a degree of nitrification of 11.5% was added to prepare a dispersion containing phosphor particles in a dispersed state. Next, tricresyl phosphate, n
-Butanol and methyl ethyl ketone were added and thoroughly stirred and mixed using a propeller mixer to prepare a coating liquid in which the phosphor particles were uniformly dispersed and the viscosity was 25 to 35 PS (at 25°C).

This coating solution was uniformly applied using a doctor blade onto polyethylene terephthalate (support material, thickness: 250 μm) into which carbon black had been kneaded, which was placed horizontally on a glass plate. After coating, the support on which the coating film has been formed is placed in a dryer,
The temperature inside this dryer was gradually raised from 25°C to 100°C to dry the coating film, thereby forming a phosphor layer with a layer thickness of 300 μm on the support.

Next, a transparent polyethylene terephthalate film (thickness: 12 μm) whose one surface had been made hydrophilic by glow discharge treatment was prepared, and a polyester adhesive was applied to the surface of the film that had not been made hydrophilic. By adhering the adhesive layer side to the phosphor layer, a stimulable phosphor sheet consisting of a support, a phosphor layer, and a protective film was prepared by attaching a protective film that also served as a hydrophilicity imparting layer. . The above glow discharge treatment of polyethylene terephthalate film is performed by attaching four semicircular rod-shaped electrodes (cross section: diameter 2 cm, length 40 cm) on an insulating plate at 10 cm intervals in a vacuum tank maintained at 0.05 mmHg. From the electrode plate composed of
Discharge voltage 3kV, processing time 3 at a distance of 15cm
The film was run under conditions of 0.4 A for 2 seconds and an electrode current of 0.4 A.

Next, as a coating for the support medium for electrophoresis, a polyethylene terephthalate film (thickness:
100 μm) was prepared.

The glow discharge treated surfaces of this polyethylene terephthalate film and the above-mentioned stimulable phosphor sheet are placed opposite each other, and a rectangular polymethyl methacrylate spacer (thickness: 1.5
A mold for forming a support medium was made by sandwiching the 2 mm), and an acrylamide Tris-borate buffer solution (acrylamide concentration: 8%, crosslinking agent ratio: 3%) prepared by a conventional method was injected into this. A slab gel (1.5 mm x 200 mm x 200 mm) was formed.

As described above, a measurement kit consisting of a stimulable phosphor sheet (supporting medium for gel electrophoresis) and a polyethylene terephthalate film (coating) having the configuration shown in FIG. Ta.

[Example 1] Isolation and radioactive labeling of DNA to be sequenced Escherichia coli plasmid DNA (pBR322) was prepared using a conventional method.
After cutting with the restriction enzyme Hind-, the 5′-
Label the ends with 32P to make double-stranded DNA (32P-labeled material)
1 μg was obtained.

5mM magnesium chloride prepared separately and
Add the above duplex to 20μ of 20mM Tris [tris(hydroxymethyl)aminomethane]/hydrochloric acid buffer (PH7.4) containing 1mM dithiothreitol.
Add 1 μg of DNA and about 1 unit of restriction enzyme Hae,
A specific decomposition reaction was carried out at 37°C for 1 hour to obtain a decomposition mixture solution containing decomposition products of the above fragments.

Using this decomposition mixture solution as a sample, use the measurement kit described above and use 50mM EDTA containing 1mM EDTA.
Electrophoresis was performed on a slab gel support at a voltage of 500 V using Tris-borate buffer (PH8.3) as an electrode solution. When the marker dye that had been added to the sample in advance reached the bottom of the gel, electrophoresis was stopped, and the origin of the coordinate axes was marked with 32P-containing ink.

Next, after exposing the above measurement kit to light to erase the noise on the stimulable phosphor sheet,
℃) in a dark box for 1 minute to carry out the exposure operation.

Next, the gel and the polyethylene terephthalate film were peeled off from the measurement kit in a dark room to obtain a stimulable phosphor sheet on which the autoradiograph of the sample had been transferred and accumulated. This stimulable phosphor sheet is introduced into a reading device as shown in Figure 2, and the position marked with 32P-containing ink is used as the origin of the coordinate axis to obtain positional information indicating the migration position of the degradation product of the 32P-labeled fragment. I read it out. Next, according to this positional information, a gel portion containing a decomposition product having a 32P label was cut out from the separated slab gel support using a thin razor, and this was transferred to a test tube.

In addition, for confirmation, after superimposing the remaining gel after performing the above partial cutting operation on the stimulable phosphor sheet again, the presence or absence of any remaining decomposition products with the 32P label was checked using a reading device. However, 32P
It was found that the entire amount of labeled decomposition products was removed. That is, it was confirmed that the positional information of the decomposition product having the 32P label obtained through the above-mentioned stimulable phosphor sheet was highly accurate.

[Brief explanation of the drawing]

1A to 1D are longitudinal sectional views showing typical embodiments of the autoradiography measurement kit of the present invention, respectively. 1a...Stormable phosphor sheet, 2a...Support for separation and development, 1b...Stormable phosphor sheet, 2b
...Support for separation and development, 3b...Coating, 1c...
...Stormable phosphor sheet, 2c...Support for separation and development, 4c...Hydrophilicity imparting layer, 1d...Stormable phosphor sheet, 2d...Support for separation and development, 3d...
Coating, 4d...hydrophilicity imparting layer. FIG. 2 shows an example of a reading device (or reading device) for reading positional information of a radiolabeled substance in a sample that has been transferred and stored on a stimulable phosphor sheet in the present invention. DESCRIPTION OF SYMBOLS 1...Stormable phosphor sheet, 2...Laser light source, 3...Laser light, 4...Filter, 5...
...beam expander, 6...optical deflector, 7
...Flat reflecting mirror, 8...Fθ lens, 9...Transfer direction, 10...Light guide sheet, 11...Photodetector,
12...Control circuit, 13...Amplifier, 14...
A/D converter, 15...signal processing circuit.

Claims (1)

[Scope of Claims] 1. A stimulable phosphor sheet having a phosphor layer made of a stimulable phosphor, and a support medium for separating and developing a living body-derived substance having a radioactive label provided on the sheet. Measuring kit for autoradiography including. 2. The autoradiography measurement kit according to claim 1, wherein the support medium for separation development is a support medium for electrophoretic separation. 3. The measurement kit for autoradiography according to claim 1, wherein the support medium for separation and development is a support medium for thin layer chromatography. 4. The stimulable phosphor sheet is substantially composed of a support, a phosphor layer made of a stimulable phosphor provided on the support, and a protective film provided on the phosphor layer. , a support medium for separating and developing a biological substance having a radioactive label is provided on the protective film. Measuring kit for autoradiography as described. 5. The autoradiography measuring kit according to claim 4, wherein the stimulable phosphor is a divalent europium-activated alkaline earth metal fluorohalide phosphor. 6. Claims 1 to 5, characterized in that the surface of a support medium for separating and developing a biological substance having a radioactive label is coated.
Measuring kit for autoradiography as described in any of the following paragraphs. 7. The autoradiography measurement kit according to any one of claims 4 to 6, wherein the surface of the protective film of the stimulable phosphor sheet is imparted with hydrophilicity. .