Binding of viruses from crude plant extracts to glutaraldehyde-treated plates for indirect ELISA

A method for binding viruses from crude plant sap to ELISA microtitre plates not precoated with antibodies is described. Plates were coated with 3-(triethoxysilyl)-propylamine, and virus particles were covalently coupled to the plate surface using glutaraldehyde. Detection of trapped viruses was carried out by an indirect ELISA procedure using crude antisera or IgGs as detecting antibodies and a protein A-peroxidase conjugate. The number of virus particles attached to the plates depended on the ratio of virus concentration to plant constituents rather than on the absolute amount of virus present in the samples. Binding of virus to glutaraldehyde-treated plates was much better than to untreated plates. Possible applications of the method for studies on the relationship and identification of plant viruses are discussed.