ELISA Detection of Various Tomato Spotted Wilt Virus Isolates Using Specific Antisera to Structural Proteins of the Virus. Min Wang, Graduate Research Assistant, Department of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York 14456. Dennis Gonsalves, Professor, Department of Plant Pathology, Cornell University, New York State Agricultural Experiment Station, Geneva, New York 14456. Plant Dis. 74:154-158. Accepted for publication 29 August 1989. Copyright 1990 The American Phytopathological Society. DOI: 10.1094/PD-74-0154.

Antibodies to electrophoretically isolated 26,000 MW nucleoprotein (26K NP) and 78,000 MW membrane protein (78K MP) of the BL isolate of tomato spotted wilt virus (TSWV) were produced. The antibodies were tested in different ELISA assays, as was a previously produced antibody from rabbit immunized with virus preparations of the BL isolate. Thirty TSWV isolates (most from the United States, a few from other countries) were analyzed and compared by ELISA with the different antibodies. All 30 isolates reacted positively in double antibody sandwich (DAS) direct ELISA with antibodies to the whole virion. Nineteen isolates were consistently detected in different ELISA tests using various antibodies, while the other 11 isolates either were not detected or were inconsistently detected in these tests. Of the 11 isolates that gave inconsistent results, eight were purified and compared by western blot. They reacted similarly to antibodies to the virion and to anti-26K NP and anti-78K MP antibodies. Most isolates of TSWV from the United States were considered to be closely related serologically. The DAS direct ELISA using antibodies to the whole virion is recommended over the use of antibodies to structural proteins for detecting a diverse selection of isolates of TSWV.