Haemophilus influenzae type b capsular polysaccharide detection and measurement by an enzyme-linked immunosorbent assay (ELISA).

A direct sandwich enzyme-linked immunosorbent assay (ELISA) was developed to detect Haemophilus influenzae type b capsular antigen. Using polystyrene as the solid phase and peroxidase-labelled rabbit antibody the assay detected the antigen in concentrations of 0.1 ng/ml. Linearity was achieved within the range of 1ng to 10 microgram/ml. Subtle measurements of Haemophilus influenzae type b capsular antigen in body fluids are possible through ELISA which is superior to counterimmunoelectrophoresis and latex-particle agglutination in this respect. ELISA should facilitate investigations concerning PRP pathogenic effects in experimental Hib infection as well as in human Hib disease.