Detection of a wide spectrum of tobacco mosaic virus strains by indirect enzyme-linked immunosorbent assays (ELISA).

The suitability of two ELISA procedures for detecting different strains of tobacco mosaic virus (TMV) by means of a single labeled antibody preparation has been determined. The specificity of the double-antibody sandwich method of ELISA was so great that enzyme conjugates prepared with antibodies to one strain did not react with closely related strains. The indirect method of ELISA which uses an antiglobulin enzyme conjugate was capable of detecting a wide range of TMV strains with antiserum to one strain only. The indirect procedure is thus better suited for diagnostic work. Both methods of ELISA were able to detect relationships between the coat proteins of different TMV strains. These results confirm that the dissociated subunits of different strains are more closely related than the corresponding intact virions.