Method for detecting biological material

1. A biological substance detection method for specifically detecting a biological substance from a pathological specimen, said method comprising the steps, in the following order, of:

activating said biological substance of said specimen;

blocking said specimen;

immunostaining said specimen with a fluorescent label;

immobilizing the immunostained specimen with an immobilization solution selected from the group consisting of formalin, paraformaldehyde, and glutaraldehyde;

morphological staining the immobilized specimen with a staining agent for morphological observation; and

mounting the morphological-stained specimen using an oil-based mounting medium comprising a resin, an organic solvent not freely miscible with water, and a discoloration inhibitor which is soluble in said organic solvent and which is selected from the group consisting of phenols derived from natural products and hindered phenols,

wherein the phenols derived from the natural products are rutin, catechin, or quercetin,

the hindered phenols are 2,6-di-tert-butyl-4-hydroxymethylphenol, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 3,5-di-t-butyl-4-hydroxybenzyl phosphonate diethyl ester, and

a section slide prepared using said oil-based mounting medium comprising said discoloration inhibitor is transparent.

2. The biological substance detection method according to claim 1 , wherein said fluorescent label comprises at least one selected from the group consisting of fluorescent dye-containing nanoparticles and fluorescent nanoparticle-containing particles.

3. The biological substance detection method according to claim 1 , wherein said organic solvent not freely miscible with water comprises at least one selected from the group consisting aromatic hydrocarbons, unsaturated hydrocarbons, ketones, esters, ethers and alcohols.

4. The biological substance detection method according to claim 1 , wherein said organic solvent not freely miscible with water comprises at least one selected from the group consisting of xylene, toluene and limonene.

5. The biological substance detection method according to claim 1 , wherein said discoloration inhibitor does not absorb light in an absorption wavelength range of 450 to 600 nm.

6. A biological substance detection kit used for the biological substance detection method according to claim 1 , said kit comprising:

an oil-based mounting medium, a discoloration inhibitor, a fluorescent label for immunostaining, and a fluorescent labeling reagent; and

an instruction manual that describes said biological substance detection method,

wherein the oil-based mounting medium comprises a resin, an organic solvent not freely miscible with water, and the discoloration inhibitor which is soluble in the organic solvent and which is selected from the group consisting of phenols derived from natural products and hindered phenols,

the phenols derived from the natural products are rutin, catechin, or quercetin, and

the hindered phenols are 2,6-di-tert-butyl-4-hydroxymethylphenol, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, or 3,5-di-t-butyl-4-hydroxybenzyl phosphonate diethyl ester.

7. A pathological specimen used for the biological substance detection method according to claim 1 ,

wherein said pathological specimen was subjected to the steps, in the following order:

the activating step the biological substance of the specimen;

the blocking step of the specimen;

the immunostaining step using the fluorescent label for specifically detecting the biological substance;

the immobilization step using the immobilization solution selected from the group consisting of formalin, paraformaldehyde, and glutaraldehyde;

the morphological staining step using the staining agent for morphological observation; and

the mounting step using the oil-based mounting medium comprising the resin, the organic solvent not freely miscible with water, and the discoloration inhibitor which is soluble in said organic solvent and which is selected from the group consisting of the phenols derived from natural products and the hindered phenols, and

wherein the pathological specimen comprises:

the oil-based mounting medium comprising the resin, the organic solvent, and the discoloration inhibitor;

the pathological specimen mounted on the medium;

the fluorescent label bound and immobilized to the biological substance; and

the staining agent contacting with the pathological specimen, and

the phenols derived from the natural products are rutin, catechin, or quercetin,

the hindered phenols are 2,6-di-tert-butyl-4-hydroxymethylphenol, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, or 3,5-di-t-butyl-4-hydroxybenzyl phosphonate diethyl ester.

8. The biological substance detection method according to claim 1 , wherein the method further comprises, after the step of mounting the morphological-stained specimen, the steps of:

observing an image produced by the immunostaining by irradiating the pathological specimen with an excitation light having a wavelength appropriate for the fluorescent label to emit fluorescence; and

observing an image produced by the morphological staining under the same observation conditions as those of a light microscope.

9. The biological substance detection method according to claim 1 , wherein the pathological specimen is a pathological tissue specimen.