DEGREASING in the histologic equipment — removal of fat from fabric structures by preparation them to studying under a microscope, and also removal of fat from the surface of slide and cover plates. If pieces of bodies before paraffin embedding or photoxylin were dehydrated (see. Dehydration ) in alcohol, ether, a xylol, chloroform, their fabric are fat-free. In other cases at production of microscopic drugs before coloring quite often make O. for elective coloring of fabrics of cuts.
It is necessary to subject to obligatory O. before coloring the frozen sections (prepared on the freezing microtome); for this purpose they are immersed for 20 — 30 min. in 96% alcohol. In some cases for O. use absolute alcohol, chloroform.
In addition to cuts, sometimes degrease pieces of fabric or even the whole bodies if it is necessary to make of them shlifa (see), napr, from completely dehydrated pieces of a bone or from not decalcified tooth.
For studying of fatty substances in these or those fabrics cuts of fabrics and bodies do not degrease. Do not subject O. cuts of fabrics and bodies and in the analysis of fabric elements by means of nek-ry gistokhy, reactions [e.g., histochemical methods of definition of lipids in fabrics (see. Lipids )].
In gistol, practice by preparation of the slide and cover plates necessary for production of microscopic drugs, it is necessary to remove fat from their surface. For this purpose they are washed out in hot soap water or in hot 2 — 3% soda solution. After O. glasses rinse in hot water and wash out several hours in running water. It is possible to degrease slide and cover plates also by processing by special solution: hot water (1000 ml), potassium bichromate (100 g), sulfuric to - that (100 g). Keep in this solution of glass 2 — 3 days, and then 1 — 2 day wash out in running water. Further not to repeat O. of slide and cover plates, they should be stored in alcohol, denatured alcohol, and also in mix of alcohol and ether (1:1).
See also Histologic methods of a research .
Bibliography: Volkova O. V. and Yelets Yu. K. Fundamentals of histology and histologic equipment, page 183, M., 1971; Histology, under the editorship of V. G. Yeliseyev, etc., M., 1972; The Small workshop on cytology, under the editorship of Yu. S. Chentsov, page 257, M., 1977; Merkulov G. A. Course of the patologogistologichesky equipment, page 102, etc., L., 1969.
L. S. Sutulov.