The Release of Antigen from Certain Bacteria on Treatment with Ether

Abstract

The bacteria investigated included several strains of Proteus, the 3 spp. of Brucella, four of Salmonella, and typhoid, tularemia and Flexner dysentery organisms, as well as a few Gram-positive forms. They were grown when possible on horse meat infusion agar. A few spp. required special media. Heavy suspensions were made in 0.85% saline containing 0.1% formalin and were treated by shaking for five seconds with an equal volume of diethyl ether and allowing the ether to remain in contact with the suspensions over night. After discarding the ether, the suspensions were centrifuged. Clear supernatants were diluted and used for precipitation tests with 1:5 dilutions of antisera prepared by immunizing rabbits with suspensions of whole homologous organisms. The most abundant precipitates were obtained with Proteus, Brucella spp. and with Pasteurella tularensis. Little or no evidence of the presence of antigen in the supernatants from the Gram positive organisms was shown.