Systematic fractionation of Schistosoma mansoni urea-soluble egg antigens and their evaluation by the single-tube, kinetic-dependent, enzyme-linked, immunosorbent assay (K-ELISA).

The application of a single-tube, kinetic-dependent, enzyme-linked, immunosorbent assay (k-ELISA) is described. The k-ELISA is simple, highly sensitive, and quantitative. With this test, the antigenic activities and cross-reactivities of several fractions from Schistosoma mansoni eggs were quantitated and compared. Particulate egg components were solubilized readily by 8 M urea, yielding antigenic fractions of high specific activities and low corss-reactivities. SDS-PAGE and activity profiles of these antigens clearly showed that they were separate and distinct form the soluble egg antigens (SEA) group. The urea-solubilized antigens appeared to be composed of two major protein bands of high molecular weights. The yield for these antigens was significantly greater than the SEA group, thus making them worthwhile candidates for serological antigens. The systematic and quantitative nature of the present study allows for the critical comparison of every antigenic fraction from S. mansoni eggs. From data of this type, a diagnostic antigen of high efficacy can be selected.