Specimen sealing method and specimen sealing device

Abstract

The present disclosure proposes a technique for sealing a specimen without using a cover glass or an organic solvent. The present disclosure proposes, as an example, a specimen sealing method for sealing a specimen section, which is an inspection target, with a cover film (including an optically transparent base material film and a water-soluble polymer coating layer), the specimen sealing method including: a step for placing the specimen section on a slide; a step for dropping water onto the specimen section or onto the slide on which the specimen section is placed; a step for, after dropping the water, placing the water-soluble polymer coating layer of the cover film on the slide so as to be on the specimen section side, and spreading the water between the cover film and the slide; and a step for, after spreading the water, drying the water.

Description

Specimen enclosing method and specimen enclosing device

[0001] The present disclosure relates to a specimen enclosing method and a specimen enclosing device.

[0002] The automation of the mounting process in pathology testing is progressing. The most common mounting method for specimens in pathology testing involves dropping an organic or aqueous mounting solution onto a stained specimen and then covering the specimen with a cover glass. However, when using a cover glass mounting method, it is difficult for the equipment to process each cover glass individually when the mounting process is automated, which can hinder speedup. In addition, there is a risk that the cover glass may break inside the equipment or that the operator may be injured by the cover glass.

[0003] In contrast, there are also encapsulation methods using a cover film that does not require a cover glass. For example, Patent Document 1 discloses a cover film that includes a light-transmitting polymer support and an abhesive binder layer made of acrylate or methacrylate. This cover film requires an organic solvent such as xylene or toluene as an activating solvent for the abhesive binder layer.

[0004] Special Publication No. 2004-506228

[0005] However, organic solvents are generally toxic, posing a risk to worker safety and necessitating the installation of a local exhaust environment. Furthermore, specimens are sometimes stained using fluorescent dyes, but the use of organic solvents can increase background fluorescence. Therefore, there is a high demand and awaited demand for an encapsulation method that does not require a cover glass or organic solvents. However, such a technology has not yet been proposed. In light of this situation, the present disclosure proposes a specimen encapsulation technology that does not require a cover glass or organic solvents.

[0006] In order to solve the above problems, the present disclosure proposes a specimen encapsulation method for encapsulating a specimen slice to be tested with a cover film (including an optically transparent base film and a water-soluble polymer coating layer), the method including the steps of placing the specimen slice on a slide, dripping water onto the specimen slice or onto the slide on which the specimen slice is placed, placing the cover film on top with the water-soluble polymer coating layer facing the specimen slice and spreading the water between the cover film and the slide, and drying the water after spreading it.

[0007] Further features related to the present disclosure will become apparent from the description of this specification and the accompanying drawings. Also, aspects of the present disclosure are achieved and realized by the elements and combinations of various elements and the aspects of the following detailed description and the appended claims. The description of this specification is merely exemplary and does not limit the scope or application of the claims of the present disclosure in any way.

[0008] According to the technology of the present disclosure, it is possible to achieve both high-speed automation of the encapsulation process and ensuring safety in the working environment.

[0009] FIG. 1 is a diagram for explaining an overview of a specimen encapsulation method according to an embodiment of the present disclosure. FIG. 2 is a diagram showing a schematic configuration example of a cover film 4. FIG. 3 is a diagram showing a configuration example of a specimen encapsulation device 100 (without a drying mechanism) according to this embodiment. FIG. 4 is a diagram showing a configuration example of a specimen encapsulation device 200 (with a drying mechanism) according to this embodiment. FIG. 5 is a diagram showing an observation image of a specimen encapsulated by the encapsulation method according to Example 1 of this embodiment, and an observation image of a specimen encapsulated by a general encapsulation method according to Comparative Example 1. FIG. 6 is a diagram showing an observation image of a specimen encapsulated by the encapsulation method according to Example 2 of this embodiment, and an observation image of a specimen encapsulated by the general encapsulation method according to Comparative Example 2.

[0010] The present disclosure provides a method and device for encapsulating a specimen in a pathological examination, which involves dropping water onto the specimen and then covering the specimen with a cover film including an optically transparent substrate film and a water-soluble polymer coating layer, thereby enabling the specimen to be encapsulated without using an organic solvent or a cover glass.

[0011] Hereinafter, embodiments and examples of the present disclosure will be described with reference to the accompanying drawings. In the accompanying drawings, functionally identical elements may be designated by the same numerals. Note that the accompanying drawings show specific embodiments and implementation examples in accordance with the principles of the present disclosure, but these are intended to aid in understanding the present disclosure and are by no means to be used to interpret the present disclosure in a limiting manner.

[0012] Although the present embodiment has been described in sufficient detail to enable those skilled in the art to practice the present disclosure, it should be understood that other implementations and forms are possible, and that changes in configuration and structure and substitutions of various elements are possible without departing from the scope and spirit of the technical ideas of the present disclosure. Therefore, the following description should not be interpreted as being limited thereto.

[0013] <Overview of Specimen Encapsulation Method> Figure 1 is a diagram illustrating an overview of a specimen encapsulation method according to an embodiment of the present disclosure. The encapsulation method according to this embodiment involves encapsulating a specimen slice 2 with water 3 and a cover film 4 (see Figure 2) including an optically transparent substrate film 5 and a water-soluble polymer coating layer 6. As shown in Figure 1, water 3 is dropped onto the specimen slice 2 or onto the slide 1 on which the specimen slice 2 is placed (Steps A and B in Figure 1). Next, the cover film 4 is placed on top with the water-soluble polymer coating layer 6 facing the specimen slice 2, and water is spread between the cover film 4 and the slide 1 (Step C in Figure 1). Finally, after spreading, the water 3 is dried (Step D: drying by natural drying or by evaporating the water with heat).

[0014] In this way, by using water 3 and cover film 4, encapsulation can be achieved without using organic solvents or cover glass. Furthermore, this encapsulation method can simultaneously speed up the automation of the encapsulation process and ensure a safe working environment. Furthermore, in the encapsulation method according to this embodiment, the specimen (specimen slice 2), water 3, and water-soluble polymer (coating layer 6) are sandwiched between the slide 1 and cover film 4, eliminating the need for organic solvents, and therefore enabling the use of slides made of resins other than glass.

[0015] <Regarding the Cover Film 4> Fig. 2 is a diagram showing a schematic configuration example of the cover film 4. The cover film 4 according to this embodiment includes an optically transparent substrate film 5 and a water-soluble polymer coating layer 6, and is formed by laminating these together. The cover film 4 can be produced based on the following design guidelines.

[0016] (i) Material of Transparent Substrate Film 5 The substrate film 5 is an optically transparent film (optically transparent means that the light transmittance does not have to be 100%, and for example, a film with a light transmittance of 90% can be used). Examples of film materials that can be used as the substrate film 5 include polyethylene terephthalate, polycarbonate, polystyrene, polycycloolefin, polymethyl methacrylate, cellulose acetate, polyurethane, silicone, and polyvinyl chloride.

[0017] (ii) Refractive Index of Transparent Substrate Film The refractive index of the substrate film 5 can be 1.35 or more and 1.70 or less, preferably 1.40 or more and 1.65 or less, and more preferably 1.45 or more and 1.60 or less. The refractive index of a cover glass generally used for encapsulation is 1.52. By making the refractive index of the substrate film 5 according to this embodiment close to 1.52, observation conditions can be made closer to those of the cover glass.

[0018] (iii) Thickness of the Transparent Substrate Film 5 The thickness of the substrate film 5 according to this embodiment can be 50 μm or more and 450 μm or less, preferably 75 μm or more and 300 μm or less, and more preferably 100 μm or more and 200 μm or less.

[0019] Generally, objective lenses for observing samples that use cover glass are equipped with a mechanism for correcting spherical aberration caused by the thickness of the cover glass. The Japanese Industrial Standards stipulate that the thickness of microscope cover glass must be between 120 μm and 170 μm. The most common cover glass correction value for objective lenses is 170 μm. By making the thickness of the substrate film 5 in this embodiment close to 170 μm, observation conditions can be closer to those of a cover glass.

[0020] (iv) Specific Gravity of Base Film 5 The specific gravity of the base film 5 according to this embodiment can be 1.05 or more, preferably 1.1 or more, and more preferably 1.2 or more. By using a material having a higher specific gravity than water as the base film 5, the cover film 4 can be easily attached to the slide 1 simply by covering it with the cover film 4, relying on gravity.

[0021] (v) Transmittance of Base Film 5 The transmittance of the base film 5 according to this embodiment for light having a wavelength of 400 nm to 750 nm can be 70% or more, preferably 75% or more, and more preferably 80% or more. The higher the light transmittance of the base film 5 in the visible region, the clearer the image obtained when observing the specimen slice 2.

[0022] (vi) Hydrophobicity / Hydrophilicity of the Base Film 5 The base film 5 according to the present embodiment preferably has a hydrophobic bulk and a hydrophilic layer on at least one side thereof that contacts the water-soluble polymer coating layer. The hydrophobic bulk prevents deformation of the base film due to swelling, and the hydrophilic layer enhances adhesion between the base film and the water-soluble polymer, thereby preventing air bubbles from entering the enclosed slide.

[0023] The hydrophilic layer can be formed by, for example, subjecting the substrate film to corona treatment, subjecting the substrate film to plasma treatment, adsorbing surfactant molecules, or adsorbing silicon dioxide particles.

[0024] The bulk hydrophobicity can be measured by the water absorption rate, and the surface hydrophilicity can be measured by the water contact angle. The substrate film preferably has a water absorption rate of 0% to 1% and a water contact angle of 0° to 90° on at least one side in contact with the water-soluble polymer coating layer, more preferably a water absorption rate of 0% to 0.5% and a water contact angle of 0° to 75° on at least one side in contact with the water-soluble polymer coating layer, and even more preferably a water absorption rate of 0% to 0.1% and a water contact angle of 0° to 65° on at least one side in contact with the water-soluble polymer.

[0025] (vii) Water-soluble polymer material constituting the coating layer 6 Examples of water-soluble polymers constituting the coating layer 6 according to this embodiment include polyvinyl alcohol, polyvinyl alcohol / polyvinyl acetate copolymer, polyvinylpyrrolidone, polyvinylpyrrolidone / polyvinyl acetate copolymer, polyethylene glycol, and polyethylene glycol derivatives. These may also be used as a mixture in any ratio.

[0026] (viii) Molecular Weight of the Water-Soluble Polymer Constituting the Coating Layer 6 The weight-average molecular weight of the water-soluble polymer according to this embodiment can be 10,000 or more, preferably 15,000 or more, and more preferably 20,000 or more. The higher the weight-average molecular weight, the stronger the adhesiveness of the water-soluble polymer, making it more difficult for the substrate film 5 to peel off from the slide 1.

[0027] (ix) Thickness of Coating Layer 6 The thickness of the water-soluble polymer coating layer 6 according to this embodiment can be from 1 μm to 60 μm, preferably from 2 μm to 30 μm, and more preferably from 3 μm to 20 μm. If the water-soluble polymer coating layer 6 is too thin, the amount of water-soluble polymer may be insufficient, resulting in the inconvenience of water not spreading over the entire surface of the cover film 4. On the other hand, if the water-soluble polymer coating layer 6 is too thick, stress may act on the substrate film 5, causing the coating layer 6 to peel off before use. Therefore, it is appropriate to keep the thickness within the above-mentioned range.

[0028] (x) Method for Coating the Substrate Film 5 with a Water-Soluble Polymer The method for coating the substrate film 5 with a water-soluble polymer (method for forming the coating layer 6) according to this embodiment is not particularly limited, but examples thereof include a method for spreading the polymer using a bar coater and a method for spreading the polymer using a spin coater.

[0029] (xi) Adhesion of the Cover Film 4 to the Slide 1 The cover film 4 according to this embodiment does not have adhesive properties until it comes into contact with water 3. Therefore, it can be rolled up and stored in a low-humidity environment. When the cover film 4 comes into contact with water 3, the water-soluble polymer coating layer 6 is dissolved, and the cover film 4 first becomes adhesive.

[0030] <Regarding Water 3> (i) Total Amount of Water 3 Dripped In this embodiment, the total amount of water 3 dripped onto the specimen slice 2 or slide 1 is not particularly limited, but can be 50 μL or more and 140 μL or less, preferably 55 μL or more and 130 μL or less, and more preferably 60 μL or more and 120 μL or less.

[0031] If the amount of water 3 is insufficient, the water-soluble polymer of the coating layer 6 may not spread over the entire surface of the cover film 4. On the other hand, if the amount of water 3 is excessive, it becomes difficult to attach the cover film 4 to the slide 1. Furthermore, it takes time for the water 3 to dry, and if too much water 3 remains on the slide 1, the refractive index of the specimen slice 2 will decrease drastically, which may result in a low resolution of the observed image.

[0032] (ii) Components that can be contained in the water 3 The water 3 to be dropped onto the slide 1 or the like can contain at least one component selected from the group consisting of a preservative, a buffer, and an antioxidant.

[0033] Including a preservative in the water 3 is expected to have the effect of improving the storage stability of the specimen slice 2. An example of the preservative is sodium azide. Furthermore, including a buffer in the water 3 is expected to have the effect of suppressing changes in the color tone of the staining dye due to changes in pH. An example of the buffer is trihydroxymethylaminomethane. Furthermore, including an antioxidant in the water 3 is expected to have the effect of suppressing changes in the color tone of the staining dye due to oxidation. An example of the antioxidant is DABCO.

[0034] (iii) Regarding drying of the water 3 dropped on the slide 1, etc., in this embodiment, there is no particular limitation on the method for drying the dropped water 3. For example, there is a method in which the water 3 is allowed to stand in a low humidity environment to dry naturally, or a method in which the slide 1 is heated, for example, from below to evaporate the water 3.

[0035] The amount of water remaining after drying the water 3 (amount of water dropped - amount of water evaporated) is not particularly limited, but is preferably 40 μL or less, more preferably 30 μL or less, and even more preferably 20 μL or less. The smaller the amount of remaining water, the stronger the adhesiveness of the water-soluble polymer of the coating layer 6 can be.

[0036] <Configuration of specimen enclosing device 100> Fig. 3 is a diagram showing a configuration example of the specimen enclosing device 100 (without a drying mechanism) according to this embodiment. Fig. 4 is a diagram showing a configuration example of the specimen enclosing device 200 (with a drying mechanism) according to this embodiment.

[0037] The specimen enclosing device 100 includes a mechanism for fixing the slide 1, a mechanism for dripping water 3, and a mechanism for feeding the cover film 4 onto the slide 1, and is configured to automate the specimen enclosing operation. For example, as shown in FIG. 3 , the specimen enclosing device 100 includes a slide holder 7 that fixes the four sides of the slide 1 with protrusions as a mechanism for fixing the slide, a dispensing nozzle 8 that drips a fixed amount of water 3 onto the slide 1 as a mechanism for dripping the water 3, a water tank 9 that stores the water 3, and a cover film support 10 that fixes the cover film 4 in a roll shape and a feed roller 11 that pulls the cover film 4 by the required amount as a mechanism for feeding the cover film 4. Note that the specimen enclosing device 100 does not include a mechanism for drying the water 3 dripped onto the slide 1 or the specimen slice 2. Therefore, the dripped water 3 evaporates by natural drying.

[0038] On the other hand, the specimen enclosing device 200 shown in Fig. 4 is provided with a mechanism for drying the dropped water 3. Specifically, in addition to the configuration of the specimen enclosing device 100 (Fig. 3), the specimen enclosing device 200 is provided with a heater 13 for heating the slide 1 from below as a mechanism for drying the water 3, and a holder conveyor 14 as a mechanism for transporting the enclosed slide 1.

[0039] EXAMPLES The present embodiment will be described in more detail below with reference to examples, although the present embodiment is not limited to the following examples.

[0040] (1) Preparation of Cover Film According to Example 1 First, the cover film according to Example 1 was prepared in the following manner.

[0041] (i) A 10 wt % aqueous solution of polyvinyl alcohol (weight average molecular weight 13,000 to 23,000) was prepared.

[0042] (ii) 2 mL of a 10 wt % aqueous solution of polyvinyl alcohol was dropped onto a 200 μm thick polycarbonate film and spread over the entire surface using a bar coater.

[0043] (iii) After leaving the film to stand for 2 hours to evaporate the water, the polycarbonate film was coated with polyvinyl alcohol to a thickness of 6 μm, and the film was cut into a size of 25 mm × 50 mm to prepare a polycarbonate cover film.

[0044] (2) Example 1 and Comparative Example 1 The encapsulation method of Example 1 and a general encapsulation method (Comparative Example 1) different from this Example 1 were used to encapsulate specimens, and the encapsulation performance was compared and evaluated.

[0045] Two immunostained specimens were prepared. DAB was used as the staining dye. One of the specimens was encapsulated using the encapsulation method of this example. Specifically, 80 μL of water was dropped onto the specimen, and the polycarbonate cover film prepared above was placed over it so that the polyvinyl alcohol-coated surface was in contact with the water. The slide was allowed to air dry, and the cover film was then attached to encapsulate the specimen.

[0046] The other slide was mounted using a standard mounting method (Comparative Example 1). Specifically, 80 μL of a commercially available aqueous mounting solution (CC / Mount) was dropped onto the specimen, and a cover glass was placed over the specimen. The slide was allowed to air dry, and the cover glass was then attached to mount the specimen.

[0047] When these mounted specimens were observed under a microscope, it was confirmed that there was no difference in the resolution of the specimen images, as shown in Figure 5 (a diagram showing the images of a specimen mounted using the mounting method of Example 1 and a specimen mounted using the mounting method of Comparative Example 1). Furthermore, 10 observations were selected from the images and the changes in staining intensity were evaluated over time every week. It was confirmed that no significant fading of the staining dye occurred in any of the mounted specimens even after 10 weeks from mounting. The mounting method of Example 1 resulted in an average fading rate of 0.11% / week, while the conventional mounting method (Comparative Example 1) resulted in an average fading rate of 0.13% / week, both of which were extremely low and imperceptible to the naked eye. In other words, the mounting method of Example 1 did not adversely affect the specimen section 2 and provided images with the same resolution as conventional mounting methods. Meanwhile, Example 1 ensured a safe working environment by eliminating the use of cover glasses or organic solvents, and also achieved automated and high-speed mounting processes.

[0048] (3) Preparation of Cover Film According to Example 2 The cover film according to Example 2 was prepared in the following manner.

[0049] (i) A 10 wt % aqueous solution of polyvinyl alcohol (weight average molecular weight 13,000 to 23,000) was prepared.

[0050] (ii) A polystyrene film 200 μm thick was subjected to corona treatment to prepare a polystyrene film 200 μm thick having a water absorption rate of 0.03% and a water contact angle of 54°.

[0051] (iii) 2 mL of a 10 wt % aqueous solution of polyvinyl alcohol was dropped onto a 200 μm polystyrene film and spread over the entire surface using a bar coater.

[0052] (iv) After leaving the film to stand for 2 hours to evaporate the water, the polycarbonate film was coated with polyvinyl alcohol to a thickness of 6 μm. The film was cut into a size of 25 mm × 50 mm to prepare a polystyrene cover film.

[0053] (4) Example 2 and Comparative Example 2 The encapsulation method of Example 2 and a general encapsulation method (Comparative Example 2) different from this Example 2 were used to encapsulate specimens, and the encapsulation performance was compared and evaluated.

[0054] Two immunostained specimens were prepared. DAB was used as the staining dye. One of the specimens was mounted using the mounting method of Example 2. Specifically, 80 μL of water was dropped onto the specimen, and the polystyrene cover film prepared above was placed over the specimen so that the polyvinyl alcohol-coated surface was in contact with the water. The slide was allowed to air dry, and the cover film was then attached to mount the specimen.

[0055] The other slide was mounted using a standard mounting method (Comparative Example 2). Specifically, 80 μL of a commercially available aqueous mounting solution (CC / Mount) was dropped onto the specimen, and a cover glass was placed over the specimen. The slide was allowed to air dry, and the cover glass was then attached to mount the specimen.

[0056] When these mounted specimens were observed under a microscope, it was confirmed that there was no difference in the resolution of the specimen images, as shown in Figure 6 (a diagram showing the images of a specimen mounted using the mounting method of Example 2 and a specimen mounted using the mounting method of Comparative Example 2). Furthermore, 10 specimens were selected from the images and the change in staining intensity was evaluated over time every week. It was confirmed that no significant fading of the staining dye occurred in any of the mounted specimens even after 10 weeks from mounting. The mounting method of Example 2 showed an average fading rate of 0.13% / week, while the general mounting method (Comparative Example 2) showed an average fading rate of 0.13% / week, both of which were so low that they were not noticeable to the naked eye.

[0057] Furthermore, when the degree of air bubble infiltration into the encapsulated slide was evaluated, the air bubble infiltration rate (area occupied by air bubbles per encapsulated area) was 0% after one month using the encapsulation method of Example 2, while the air bubble infiltration rate was 2% using the general encapsulation method (Comparative Example 2).

[0058] In other words, it was found that the mounting method of Example 2 does not adversely affect the specimen slice 2, can obtain an observation image with the same resolution as that obtained by a conventional general mounting method, and further, prevents the intrusion of air bubbles more effectively than the conventional general mounting method. On the other hand, according to the example, a safe working environment can be ensured by not using a cover glass or organic solvent, and the mounting process can be automated and accelerated.

[0059] REFERENCE SIGNS LIST 1 Slide 2 Specimen slice 3 Water 4 Cover film 5 Base film 6 Coating layer 7 Slide holder 8 Dispensing nozzle 9 Water tank 10 Cover film support 11 Delivery roller 12 Cutter 13 Heater 14 Holder conveyor

Claims

1. A method for encapsulating a specimen slice to be examined with a cover film, the cover film including an optically transparent base film and a water-soluble polymer coating layer, the method comprising the steps of: placing the specimen slice on a slide; dripping water onto the specimen slice or onto the slide on which the specimen slice has been placed; after dripping the water, placing the cover film with the water-soluble polymer coating layer facing the specimen slice and spreading the water between the cover film and the slide; and, after spreading the water, drying the water.

2. A method for encapsulating a specimen according to claim 1, wherein the base film is made of polyethylene terephthalate, polycarbonate, polystyrene, polycycloolefin, polymethyl methacrylate, cellulose acetate, polyurethane, silicone, or polyvinyl chloride.

3. A method for encapsulating a specimen according to claim 1, wherein the refractive index of the substrate film is 1.35 or more and 1.70 or less.

4. A method for encapsulating a specimen according to claim 1, wherein the thickness of the base film is 50 μm or more and 450 μm or less.

5. A method for encapsulating a specimen according to claim 1, wherein the specific gravity of the base film is 1.05 or more.

6. A method for encapsulating a specimen according to claim 1, wherein the transmittance of the base film to light with wavelengths of 400 nm to 750 nm is 70% or more.

7. A method for encapsulating a specimen according to claim 1, wherein the base film is hydrophobic in bulk and has a hydrophilic layer on at least one side that contacts the coating layer of the water-soluble polymer.

8. A method for encapsulating a specimen according to claim 1, wherein the base film is hydrophobic in bulk and has, on at least one side in contact with the coating layer of the water-soluble polymer, a hydrophilic layer formed by corona treatment, a hydrophilic layer formed by plasma treatment, a hydrophilic layer formed by adsorbing surfactant molecules, or a hydrophilic layer formed by adsorbing silicon dioxide particles.

9. A method for encapsulating a specimen according to claim 1, wherein the base film has a water absorption rate of 0% or more and 1% or less, and at least one surface in contact with the coating layer of the water-soluble polymer has a water contact angle of 0° or more and 90° or less.

10. A method for encapsulating a specimen according to claim 1, wherein the base film has a water absorption rate of 0% or more and 0.5% or less, and at least one surface in contact with the coating layer of the water-soluble polymer has a water contact angle of 0° or more and 75° or less.

11. A method for encapsulating a specimen according to claim 1, wherein the base film has a water absorption rate of 0% or more and 0.1% or less, and at least one surface in contact with the coating layer of the water-soluble polymer has a water contact angle of 0° or more and 65° or less.

12. A method for encapsulating a specimen according to claim 1, wherein the water-soluble polymer constituting the coating layer is polyvinyl alcohol, polyvinyl alcohol / polyvinyl acetate copolymer, polyvinylpyrrolidone, polyvinylpyrrolidone / polyvinyl acetate copolymer, polyethylene glycol, a polyethylene glycol derivative, or a mixture thereof.

13. A method for encapsulating a specimen according to claim 1, wherein the weight-average molecular weight of the water-soluble polymer constituting the coating layer is 10,000 or more.

14. A method for encapsulating a specimen according to claim 1, wherein the total amount of water dropped onto the specimen slice or slide is 50 μL or more and 140 μL or less.

15. A method for encapsulating a specimen according to claim 1, wherein the water dropped onto the specimen section or the slide contains at least one of a preservative, a buffer, or an antioxidant.

16. The method for enclosing a specimen according to claim 1, wherein the step of drying the water includes allowing the water to dry naturally or heating the slide to evaporate the water.

17. A method for encapsulating a specimen according to claim 1, wherein the amount of water remaining after the drying process in the step of drying the water is 40 μL or less.

18. A specimen enclosing device that encloses a specimen slice to be examined with a cover film, comprising: a slide fixing mechanism that fixes a slide on which the specimen slice is placed; a water dripping mechanism that drips water onto the slide or specimen slice fixed by the slide fixing mechanism; and a film delivery mechanism that is fixed to the slide fixing mechanism and delivers a cover film that includes an optically transparent base film and a coating layer of a water-soluble polymer onto the slide or specimen slice on which the water has been dripped.

19. A specimen encapsulation device according to claim 18, further comprising a slide heating mechanism for heating the slide.

20. A specimen encapsulation device according to claim 18, further comprising a slide transport mechanism for transporting the slide.

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