VIEW ARTICLE

Techniques

Development of a Solid-Phase Radioimmunoassay for Detection of Soybean Mosaic Virus. G. R. Bryant, Department of Microbiology, Iowa State University, Ames 50011; D. P. Durand(2), and J. H. Hill(3). (2)Department of Microbiology, Iowa State University, Ames 50011; (3)Department of Plant Pathology, Seed and Weed Sciences, Iowa State University, Ames. Phytopathology 73:623-629. Accepted for publication 3 November 1982. Copyright 1983 The American Phytopathological Society. DOI: 10.1094/Phyto-73-623.

A direct sandwich solid-phase radioimmunoassay (SPRIA), using antibody-coated polystyrene beads, was developed for the detection and quantification of soybean mosaic virus (SMV) in soybean seeds. Virus-specific IgG was passively adsorbed to the solid-phase bead surface, and virus antigen, bound by the immobilized antibody, was detected by subsequent binding of anti-SMV IgG labeled with ³H. SPRIA values (or bound radioactivity) were generally proportional to virus concentration with a detection limit of 25- 50 ng of purified SMV per milliliter. Extracts from healthy seeds did not interfere with virus detection. Extracts from infected and uninfected seeds could be differentiated, and the approximate level of infection could be estimated by using SPRIA. Because of its technical simplicity, reproducibility, and versatility, SPRIA is useful for detecting SMV in individual and bulked seeds.