Use of Monoclonal Antibody in an Enzyme-Linked Immunosorbent Assay to Detect the Presence of Trichoplusia ni (Lepidoptera: Noctuidae) S Nuclear Polyhedrosis Virus Polyhedrin in T. ni Larvae

Abstract

A sandwich type of enzyme-linked immunosorbent assay (ELISA) incorporating monoclonal antibody and rabbit immune serum was used to detect polyhedrin in Trichoplusia ni S nuclear polyhedrosis virus (TSN)-infected T. ni (Hubner) larvae. Polyhedrin, the major component of nuclear polyhedrosis virus (NPV) polyhedra, is coded for by the virus, and its presence in larvae indicates the presence of NPV or an NPV infection. The ELISA and the judgment of a trained observer were compared with regard to detecting NPV or NPV disease in larvae exposed to high, medium, and low doses of TSN. The ELISA was the more sensitive diagnostic technique of the two, and detected the presence of NPV 2 to 3 days in advance of the observer. At the medium and high dosages, the ELISA detected polyhedrin in or on larvae 2 h after exposure to the virus, before any protein amplification could have taken place, indicating a high degree of assay sensitivity.