The enzyme-linked immunosorbent assay of meningococcal and some related Escherichia coli polysaccharides

A non-competitive enzyme-linked immunosorbent assay (ELISA) system has been developed for the quantitative, sensitive and specific determination of meningococcal polysaccharides. A prerequisite, however, is the correspondence of the O -acetyl content and the molecular size of the polysaccharides in the samples and the reference preparation. If these characteristics differ, special precautions in the use of antibodies to both the O -acetylated and the non- O -acetylated variants have to be taken, including the testing of the sample in at no less than three dilutions.