Influence of ELISA conditions on detection of serological relationships among luteoviruses

Three variations in the ELISA procedure were used in an attempt to understand the basis for serological relationships among three isolates of barley yellow dwarf virus (BYDV-RPV-I from Illinois, BYDV-RPV-N from New York and BYDV-PAV from Illinois), beet western yellows virus (BWYV) and soybean dwarf virus (SDV). Detection of serological relationships was dependent on the state of the virus particle (e.g. dissociated or intact) and the method of detection (e.g. direct or indirect). In indirect ELISA, where virus particles were dissociated due to incubation in a high pH buffer, all five virus isolates were serologically related. In double antibody sandwich (DAS) ELISA, identification of serological relationships was based on detection of epitopes associated with intact virus particles, which resulted the detection of fewer serological relationships. Direct ELISA showed, depending on the Ig, that the state of the virus particle and/or the method of detection did effect the ability to detect some serological relationships.