Comparative study of antigenic properties of potato virus X and its coat protein in solution and after adsorption to...

Different ELISA procedures were used to compare the antigenic properties of intact potato virus X (PVX) and its dissociated protein. It was found that when the reaction took place in solution (competition ELISA), the intact virus reacted with polyclonal antibodies against the intact PVX (Ab-PVX) much more strongly than did the dissociated PVX coat protein (Pr), and the dissociated protein reacted with the homologous polyclonal antibodies (Ab-Pr) more strongly than did the intact PVX. However, if these two antigens were absorbed directly to polystyrene wells (in direct ELISA), they acquired similar reactivities with Ab-Pr, while the intact PVX still reacted more strongly with the Ab-PVX than did the dissociated protein. Differences in reactivity with Ab-Pr and Ab-PVX were not observed between PVX absorbed to polystyrene plate wells (direct ELISA) and to immunoglobulin-coated wells (double antibody sandwich ELISA). These results are not in agreement with the currently accepted view of PVX virions disruption (denaturation) upon adsorption to plastic.