Biotin-avidin-amplified enzyme immunoassay for detection of herpes simplex virus antigen in clinical specimens

Abstract

A biotin-avidin-amplified enzyme-linked immunosorbent assay (B-A ELISA) was developed to detect herpes simplex virus type 1 (HSV-1) and HSV-2 antigens in clinical specimens. The test was designed as a solid-phase, double-antibody, sandwich assay in which plates were coated with a polyclonal rabbit IgG anti-HSV reagent; the sandwich antibody was a biotin-labeled mouse IgM monoclonal antibody that reacts with a common antigen associated with HSV-1 and HSV-2. The test can be completed in 4 h if antibody-coated plates are available. The detection limit of the B-A ELISA, determined by titration of virus stocks, was .apprx. 90 plaque-forming units or 6 .times. 103 physical particles of HSV-1 or HSV-2/50 .mu.l of virus stock. The following results were obtained in a study in which swabs were taken from a variety of lesions and assayed for infectivity in tissue culture and by B-A ELISA. Of 421 suspected HSV lesions tested, 69 were positive by both tests and 159 were negative by both tests; 122 were positive by B-A ELISA but negative for infectivity; 71 were negative by B-A ELISA but contained infectious virus. The HSV specificity of the assay was substantiated by partial blocking of reactivity with rabbit IgG anti-HSV and by the absence of reactivity with a nonspecific biotin-labeled mouse IgM monoclonal antibody.