The Virus of Psittacosis

Abstract

The virus of psittacosis was propagated on the chorio-allantoic membrane of the developing egg for over 38 months without any loss of infec-tiousness for white mice of a common stock. Over 425 bacteria-free passages have yielded material for a study of the developmental cycle of the virus and for preparation of purified suspensions of elementary bodies. The L.C.L. bodies were freed of soluble protein and concentrated by washing with petroleum ether, tryptic digestion and differential centrifugation. The elementary body suspensions were standardized by direct count in the Petroff-Hausser chamber and by opacity. The purified suspensions were as infectious as crude material and the infectiousness paralleled the number of elementary bodies in the suspension. The vims was resistant to the action of petroleum ether and purified trypsin.