SILVERINGS METHODS (synonym methods of impregnation by silver) — ways of identification of fabric and cellular components (structures) by treatment of tissue specimens silver salts. Pages of m belong to methods of impregnation of fabric structures salts of metals (see. Impregnation ). Recovery (reduction) of metal silver leads to sedimentation of eFO on certain structures, to-rye gain brown or black color. Among fabric components distinguish argentaffin, in to-rykh a reduction of silver it is carried out in the dark due to their own recovery properties (see. Argentaffin cells ), and argyrophil, in to-rykh silver it is besieged only under the influence of light or chemical reducers (see. Argirofilnost ). S.'s essence of m remains not quite clear, the majority of these methods is based on empirical developments. Apparently, in a phenomenon of an argentaffinnost a certain role belongs to presence at cells of derivatives catecholamines (see), and development of an argirofiliya is connected, in, particulars, with existence in fabric components of sulphhydryl groups (SH-group) and unsaturated fat to - t.
From silver salts for S. m usually use 0,5 — 20% solutions of silver nitrate, is frequent in the form of ammoniac silver (see. Bilshovsky — Groce — Lavrentyeva a method ). Apply also acetate, a carbonate, picrate, a lactate of silver, protargol, etc. In all cases for S. chemically pure reactants and ware are required for m; it is necessary to work with glass needles, avoiding contact of drugs with metal.
Depending on the purpose C. of m carry out or on fresh, unstable drugs, or after fixing, 10 — 20% solution of formalin are more often. Without S.'s fixing m reveal intercellular borders of an epithelium and mesothelium (see. Ranvye methods ). Silver can serve also as the agent fixing fabric. The fixing properties of solutions of silver use at impregnation of a vystilka of alveoluses by Ebert's method when they through a bronchial tube or a trachea fill a share or all lung of 0,5% with solution of silver nitrate with the subsequent UF-ob-lucheniyem of frozen sections of a lung, and also for identification of neurofibrilla in fresh pieces of tissue of brain (see. Ramón-and-Kakhalya methods ).
Dean and the Fruit drink (N. of W. Deane, A. Morse, 1948) recovery properties ascorbic to - you (redoxon) for identification of its inclusions in fabrics suggested to use: fresh pieces of fabric process saturated solution of silver nitrate in mix of alcohol, water and ice acetic to - you, then transfer them to an acid fixative, dehydrate and fill in in paraffin. Under a microscope of inclusion of redoxon are observed in the form of black points.
On the fixed drugs C. of m allow it is elective to reveal many elements of nervous tissue (nervous cells, neurofibrilla, a neuroglia, axial cylinders and nodes of myelin nerve fibrils, amyelinic fibers, nerve terminations), argyrophil fibers of connecting fabric, argentaffin cells of a stomach and intestines (argentaffinotsita), chromaffin cells of adrenal glands and paragangliyev, nek-ry pigments, and also lime (see. Kossa ways ), etc. Methods of silvering apply also in bacteriology (see. Levaditi method ), virology (see. Morozova method ), cytology — impregnation of a complex of Golgi (cm, Golgi complex ), identification of nucleolar organizers (see. Kernel ).
A number of options C. of m is developed for identification of certain elements of nervous tissue in various parts of the nervous system. These options differ on composition of the fixing mixes p to ways of a reduction of silver. So, elements of nervous tissue study or by processing by silver of the whole pieces of fabric (total impregnation) with the subsequent sectioning, napr, at total impregnation with pyridine across Bilshovsky, option of this way — Bouquet's method, and also during the use of methods of Golgi, Ramón-and-Kakhalya (see. Golgi method , Ramón-and-Kakhalya methods ), or by impregnation of frozen sections (the cm, Bilshovsky — grew — Lavrentyeva a method, Miyagava — Aleksandrovskoy a method , Ortega methods ). Peripheral nerves and their terminations well come to light by a method of Campos representing modification of a method of Bilynovsky — Groce — Lavrentyeva.
For silvering argyrophil fibers (see) on cuts of connecting fabric apply various options offered in 1904 for identification of neurofibrilla of a method Beale-shovsky (see Bilshovsky — Groce — Lavrentyeva a method). Mares (R. Ma-resch, 1905) this method applied to impregnation of fibrilla of connecting fabric. In Foote's method before impregnation to Bilshovsky's method frozen sections process р-рами^перманганата potassium and oxalic to - you. Impregnation of argpro-filny fibers by the Vallgre-na method is almost not applied now. Apply also Achu-karro's method in Ortega's modifications (R. of del Rio Hortega) to frozen sections and Klarfeld — for celloidin sections (see Ortega methods). Good results are yielded also by the methods offered by P.E. Snesarev for the frozen and paraffin sections (see. Snesareva methods ).
At all S. the bystry termination of silvering is reached by m by immersion of drugs in ammonium hydroxide (the solution of ammonia divorced three times 25%). Excess sedimentation of silver can be eliminated with a differentiation in 0,25% solution of potassium permanganate, 2% solution of ammonium persulphate, etc. After S.'s use the m cuts can be tinted solutions of salts of gold (see. Gilding methods ).
See also Histologic methods of a research .
Bibliography: Lilly P, the Patogistologichesky equipment and a practical histochemistry, the lane with English, page 216, 222, M., 1969; Merkulov G. A. Course of the patologogistologichesky equipment, page 181, JI., 1969; R about m e y with B. Mikroskopicheskaya of the technician, the lane with it., page 309, M., 1954.
Ya. E. Hesinonim