A solid-phase radioimmunoassay for polyhedron protein from baculoviruses.

A solid-phase radioimmunoassay has been developed for detecting polyhedron protein of Wiseana spp. nuclear polyhedrosis virus (W.NPV) using antigen fixed to plastic microtiter wells. The direct assay using 125I-labeled rabbit immunoglobulins could detect 0.2 microng of polyhedron protein, and the indirect method using 125I-labeled sheep antirabbit immunoglobulins could detect 0.05 microng of polyhedron protein. Antibodies against W.NPV polyhedron protein could be detected using a competition assay with labeled and unlabeled antibodies, providing a method suitable for rapid and quantitative screening of sera.