Characterization of fractions containing the thermostable agglutinogens of Neisseria gonorrhoeae.

Extract was prepared by heat treatment (100 degrees C. 2 h) of bacteria of N. gonorrhoeae strain 8551. The acid precipitate (pH 2.5) of the extract was resolved by gel chromatography (Sepharose CL-6B) into material eluted with the void volume (Fr. I) and material retarded by the column (Fr. II). Fr. I contained at least three precipitinogens, the antigenic determinant a of LPS and the protein determinant b. The antigens demonstrable in Fr. I were also detected in an outer membrane preparation obtained by extraction of the bacteria with a lithium acetate buffer. Fr. II contained LPS and several other precipitinogens. The antigens of Fr. I included the heat stable agglutinogens of the gonococcus, and antibodies of these could be raised by immunization of rabbits with the Fr. I material.