Nonspecific binding of immunoglobulins to coat proteins of certain plant viruses in immunoblots and indirect ELISA.

Nonspecific binding of immunoglobulins to coat protein of cucumber mosaic virus and several other plant viruses was observed in Western immunoblots, and to a much lesser extent in enzyme-linked immunosorbent assays. The binding appears to occur between immunoglobulin molecules and the basic domains of viral coat proteins which bind to RNA during encapsidation. In all cases tested, the nonspecific reactions could be prevented by addition of 5 U/ml of heparin to the incubation buffers.