[Use of polyvinyl alcohol for preparing frozen histological sections]

The authors developed a new method for preparation of frozen histological sections. It consists in the use of glycerin-plastified polymer, polyvinyl alcohol, and distilled water for impregnation of tissue pieces and subsequent freezing of them in the same medium. This produces histological sections of high quality. The frozen sections are sufficiently thin (3--5 micrometers). The method excludes cell structure destruction by ice crystals and overfreezing of blocks; the sections do not crumble. Losses of free cell elements, extraction of substances and other artifacts are minimized. The frozen histological sections are firmly glued to the glass without using protein with glycerin. The method saves time and reagents for the preparation of the sections and allows their wide use in morphological and histochemical studies.