What is the best fixative for frozen sections?
Answer. Unfixed tissue, cut with a cryostat (thin sections) or a vibrating microtome (thick sections) should be fixed if this is compatible with the staining technique to be used. Many enzyme histochemical methods demand unfixed sections, and so do immunohistochemical methods with some (fortunately not most) primary antibodies. Enzyme incubations are often terminated by moving the slide or coverslip bearing the cryostat section from the incubation medium into a neutral, buffered formaldehyde fixative. Even “minimal” (= inadequate) fixation before staining will greatly improve the structural preservation of tissue. Many enzymes will survive either a minute or two in neutral, buffered formaldehyde, followed by a wash in buffered saline. Some enzymes and most antigens will survive immersion of the slide or coverslip in cold (about 0 C) acetone for half a minute. The acetone is allowed to evaporate before immersing the section in incubation medium. Cryostat sections may also be fixed by he
Answer. Unfixed tissue, cut with a cryostat (thin sections) or a vibrating microtome (thick sections) should be fixed if this is compatible with the staining technique to be used. Many enzyme histochemical methods demand unfixed sections, and so do immunohistochemical methods with some (fortunately not most) primary antibodies. Enzyme incubations are often terminated by moving the slide or coverslip bearing the cryostat section from the incubation medium into a neutral, buffered formaldehyde fixative. Even “minimal” (= inadequate) fixation before staining will greatly improve the structural preservation of tissue. Many enzymes will survive either a minute or two in neutral, buffered formaldehyde, followed by a wash in buffered saline. Some enzymes and most antigens will survive immersion of the slide or coverslip in cold (about 0 C) acetone for half a minute. The acetone is allowed to evaporate before immersing the section in incubation medium. Cryostat sections may also be fixed by he
