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FREEZE‐SUBSTITUTION
Author(s) -
Ahlqvist Johan
Publication year - 1972
Publication title -
acta pathologica microbiologica scandinavica section a pathology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.909
H-Index - 88
eISSN - 1600-0463
pISSN - 0365-4184
DOI - 10.1111/j.1699-0463.1972.tb02162.x
Subject(s) - dehydration , wax , liquid nitrogen , toluene , fixation (population genetics) , substitution (logic) , quenching (fluorescence) , paraffin wax , ethanol , materials science , chemistry , chromatography , biochemistry , organic chemistry , composite material , physics , quantum mechanics , computer science , fluorescence , gene , programming language
By the method of freeze‐substitution described, specimens about or less than 2 mm thick and not unduly large in other directions may be processed; in most other methods of freeze‐substitution smaller pieces of tissue are used. Throughout the process the tissue slices are kept in commercial stainless steel tissue baskets. Quenching is performed with Freon 22 chilled with liquid nitrogen. Freeze‐substitution for 40 hours at —42 + 1 C and a subsequent step called final dehydration for 2 hours at about —6 C are performed with ethanol, clearing for 90 min with toluene at the latter temperature, all under effective shaking. Tissues are embedded in paraffin waxes. Different flotation and post‐fixation methods have been tested. The method enables one to use at least some immunofluorescent and some histochemical enzyme methods. The morphology of the tissue with a few exceptions is good.