Complement Fixation with Leptospiral Antigens

Abstract

The complement fixing activity of prepns. from leptospiral cultures and from chick embryos infected with leptospirae was studied in the presence of immune rabbit serum. Culture supernatant fluids tended to be anti-complementary with a low antigenicity that tended to increase with the temp. and time of incubation. After lysis of the organisms by the addition of Na desoxycholate to cultures, the complement fixing activity of the supernatant fluid was increased still further. Boiling infected allantoic fluids with [image]/5 NaOH yielded a soluble non-dialyzable antigen. Supernatant fluid from L. pomona culture, alkali-treated allantoic fluids, and washed suspensions of leptospirae from allantoic fluids reacted specifically with L. pomona immune rabbit serum in the dilutions employed.