From Big Medical Encyclopedia

LEVADITI METHOD ( S. Levaditi , fr. bacteriologist, immunologist and virologist. 1874 — 1953) — impregnation of a pale treponema of Shaudinn caustic silver in a piece of the studied material. L. m apply to studying of topographical distribution of treponemas in the struck bodies and fabrics. There are two options of silvering of a pale treponema across Levaditi.

The original method is used preferential during the studying of inborn syphilis. The studied fabric is processed as follows: 1) pieces 1 — 2 mm thick fix 10% solution of formalin during 24 hours; 2) quickly wash out a distilled water and condense 96% with alcohol during 24 hours; 3) wash out a distilled water; 4) impregnate 1,5 — 3% solution of silver nitrate in the cleared bottles from dark glass, bottletight a ground stopper, within 3 days at t ° 38 °; 5) quickly wash out a distilled water; 6) recover the mix consisting from pyrogallic to - you are the 4th, 40% of formalin — 5 ml, a distilled water — 100 ml, during 24 — 48 hours at a room temperature; 7) wash out a distilled water, carry out through alcohols of the ascending fortress, a xylol and fill in in paraffin; serial sections no more than 5 microns thick paste albumine on carefully purified slide plates and dry up during 24 hours at t ° 37 °; 8) after removal of paraffin a xylol cuts are concluded in neutral Canada balsam. On successful drug a background light yellow without any precipitations, treponemas — black. For specification of an intracellular arrangement of treponemas impregnirovanny cuts dokrashivat aniline dyes: a) dewaxed drugs are painted with Romanovsky's solution — Gimza (1: 20) within several minutes, wash out a distilled water, differentiate mix of clove-stems oil with absolute alcohol (1: 10) also conclude in Canada balsam; b) coloring of dewaxed cuts is made the concentrated solution of toluidine blue, differentiate absolute alcohol with several drops glycerin-ether across Unna and concluded in Canada balsam. Treponemas at the same time are painted in black color, kernels of connective tissue cells, an epithelium, leukocytes get a blue shade, a background of drug green.

The second option — Levaditi's method — Manuelyana — is recommended for studying and diagnosis of primary and secondary syphilis at the person and for studying of an experimental infection at animals. The first three stages correspond to an original method. Further carry out: 1) impregnation by the mix consisting of pyridine — 10 ml, 1% of solution of silver nitrate — 90 ml, during 2 — 3 hours at the room temperature and 3 — 5 hours at t ° 45 — 50 ° (in dark bottles); 2) washing with a distilled water; 3) recovery by mix from pyridine — 17 ml, acetone — 10 ml, 4% of solution pyrogallic to - you are the 90th ml at the room temperature during 3 — 5 hours; 4) washing, preparation of paraffin blocks and further processing of thin sections, as at the first option.

See also Silverings methods .

Bibliography: Levaditi C. Sur la coloration du Spirochaeta pallida Schaudinn dans les coupes, C. R. Soc. Biol. (Paris), t. 59, p. 326, 1905; it, L’histologie pathologique de la syphilis of h£reditaire, Ann. Inst. Pasteur, t. 20, p. 41, 1906; Levaditi C. et Manouelian, Nouvelle of m£thode rapide pour la coloration des spirochetes sur coupes, G. R. Soc. Biol. (Paris), t. 60, p. 134, 1906.

P. M. Shen.