Use of Direct Antigen Coating and Protein A Coating ELISA Procedures for Detection of Three Peanut Viruses

Abstract

Direct antigen coating (DAC) and protein A coating (PAC) forms of indirect enzyme-linked immunosorbent assay (ELISA) were standardized and compared with the double-antibody sandwich (DAS) form of direct ELISA for their usefulness in the detection of three peanut viruses: peanut mottle virus (PMV), tomato spotted wilt virus (TSWV), and Indian peanut clump virus (IPCV). PMV was detectable in peanut [Arachis hypogaea] seeds and pea [Pisum sativum] tissue at a 1:10,000 dilution in buffer with the DAC and at a 1:1,000 dilution with the PAC procedures. With the DAS procedure, PMV was detectable in pea tissue at a 1:1,000 dilution and in peanut seed at a 1:100 dilution. TSWV was detectable in peanut leaves at a 1:1,000 dilution with the DAC method and at 1:100 with the PAC and DAS methods. IPCV was detectable in peanut leaves at a 1:100 dilution by the DAC, PAC, and DAS methods. Sensitivity of DAC and PAC methods was, therefore, comparable to that of the DAS procedure under the short incubation period (1-2 hr at 35 C) conditions employed in the experiments.