The serological classification of Neisseria Gonorrhoeae: I. Isolation of the outer membrane complex responsible for serotypic specificity*

Abstract

Neisseria gonorrhoeae has been subdivided into several classes of serologically distinct groups. The serotyping system is based upon the antigenic specificity of a protein serotype antigen. This protein is the major polypeptide of the outer membrane of the gonococus and accounts for over 60% of that membrane’s total protein. The serotype antigen complex was isolated by mild extraction of intact organisms in 200 mM lithium acetate buffer, pH 6.0 with 10 mM EDTA for 2 h at 45°C. The extract was fractionated on Sepharose 6B and partially purified by precipitation at pH 4.2 by addition of 10% (vol/vol) acetic acid. Each serotype antigen has a unique subunit molecular size as determined by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Preliminary typing of a gonococcal strain may be performed by comparative SDS-PAGE. To date, 16 different serotypes, representing a diverse distribution, have been isolated. © 1976, Rockefeller University Press., All rights reserved.