PETRI CUP (J. R. Petri, is mute. the microbiologist, 1852 — 1921) — the ware used in bacteriological laboratory for cultivation of bacteria on dense mediums. It is offered in 1887 Mr. of Petri, R. Koch's assistant. The same cups were offered in 1885 by the Russian doctor L. L. Geydenreykh. The item of h consists of two flat small glass cups, one of which serves as a cover (fig.). Diameter and P.'s height of h are various. Usual P. of h has to dia. 10 cm, and height — 1,5 cm.
Items of h do of the neutral glass which is a little leached at a sink and sterilization. For hypodispersion of a medium P.'s bottom of h shall be equal and flat. H make a spill of nutrient mediums in P. on equal, strictly horizontal table. In P. h spill the medium melted and cooled to 55 °. H make calculation of colonies in P., looking through them on light therefore they shall be transparent.
See also Laboratory glassware .
Bibliography: Timakov In, D. and D. M Goldfarb. Fundamentals of experimental medical bacteriology, M., 1958; Petri R. J. Uber die Methoden der mo-dernen Bakterienforschung, Hamburg, 1887.
Ya. A. Parnes.