IMMUNOLOGY AND SEROLOGY OF ANAPLASMA MARGINALE. I. FRACTIONATION OF THE COMPLEMENT-FIXING ANTIGEN.

Rogers, Thomas E. (Louisiana State University, Baton Rouge), Richard J. Hidalgo, and George T. Dimopoullos. Immunology and serology of Anaplasma marginale. I. Fractionation of the complement-fixing antigen. J. Bacteriol. 88:81-86. 1964.-Studies were conducted to fractionate and purify the complement-fixation (CF) antigen of Anaplasma marginale in infected erythrocytes of cattle. Initial attempts were made to resolve the antigen from crude stromatal preparations by various chemical and physical methods. Fractionation procedures involving partial and total lipid extraction suggested that the CF antigen was lipoprotein in nature. Fluorocarbon deproteinization of stromatal antigens was also attempted. A method was developed for the preparation of a desirable Anaplasma CF antigen which involved disintegration of infected erythrocytes by sonic vibration and separation of the antigen by differential centrifugation. Antigens prepared by this method were highly specific, colorless, did not exhibit anticomplementary activity, and possessed higher titers than standard Anaplasma antigens. When density-gradient sedimentation was applied to sonic extracts of infected cells, it was demonstrated that the CF antigen could also be fractionated by this method.