From Big Medical Encyclopedia

PETRANYANI WEDNESDAY (G. Petragnani, the ital. bacteriologist and the histologist, a sort in 1893) — the elective medium for allocation of mycobacteria of tuberculosis containing bactericidal dye (malachite green). Growth of the accompanying microorganisms lingers on P. of page. The item of page consists of eggs, milk, potato starch, juice of potatoes, peptone (or asparagine), glycerin and malachite green. For preparation of the environment in a sterile liter flask with glass balls pour 0,25 l of whole cow's milk, then add during the stirring 6 g of potato starch, 1 g of peptone (or 1,25 g of asparagine) and one small cut tuber of potatoes size about egg. The flask with mix is immersed in the boiling water bath and warmed up at constant stirring by roundabouts within 10 min. before uniform jelling of contents. The flask is left on the water bath apprx. 1 hour, then removed. After temperature of mix decreases to 50 — 60 °, in it pour in contents of four fresh eggs and one more yolk during the stirring. Then add during the stirring 12 ml of glycerin and 6 ml of 2% water (on a distilled water) solution of malachite green. Filter through a double layer of a sterile gauze, spill in sterile test tubes and subject to coagulation within 30 min. at t ° 85 °, having laid test tubes in inclined situation in Koch's device. For ensuring sterility of P. of page in the next 2 days of a test tube warm up within 15 min. at t ° 75 °. For prevention of drying of the environment at storage of a test tube close sterile rubber caps. Ready P. of page has green color and contains enough water of condensation. Growth on P. the page of mycobacteria of tuberculosis of different types has characteristic differences and it is found in 2 — 4 weeks after crops. During the replacement of peptone with asparagine optimal conditions for allocation of mycobacteria of tuberculosis are created.

See also Mediums .

Bibliography: The guide to microbiological diagnosis of infectious diseases, under the editorship of K. I. Matveev, page 270, M., 1973; With and 1 m e t t e A., B o q u e t A. et N yo g r e L. Manuel technique de microbio-logie et serologie, p. 526, P., 1933.

A. I. Togunova.