An investigation ofNeisseria gonorrhoeaeby a red cell sensitization technique

Two antigens, probably polysaccharide in nature, were extracted from smoothgonococci. One of these could be adsorbed on to red cells and sensitized these cells to the action of a gonococcal antiserum. The factors concerned in this adsorption were investigated. The antigen, which was shown by a mirror absorption technique to be of two distinct types, was lost with the S-R change. The second antigen was detected by its ability to fix complement in the presence of an immune serum. It is suggested that these two antigens form a complex which determines the nature of the surface of the smooth gonococcus. I wish to thank Dr J. C. Thomas, Provincial Pathologist, for the facilities for carrying out these investigations; Prof. M. van den Ende and Dr A. Kipps for helpful and constructive criticism; and Miss E. Bennett, Miss B. Jefferies, Mr L. Heitman, Mrs S. Maddison, and Mr G. C. Buckle for technical assistance.