Antigenic analysis of excretory-secretory products of Wuchereria bancrofti and Brugia malayi infective larval forms by SDS-PAGE.

Excretory-secretory (ES) products of W. bancrofti and the closely related B. malayi infective larval forms were analysed for their antigenic activity by SDS-PAGE followed by Western blotting as well as by gel elution-sandwich ELISA using filarial serum immunoglobulin-G (FSIgG) as a capture antibody. In W. bancrofti infective larval ES products, the protein molecules of 66, 46, 35, 33, 30 and 14 kDa molecular wt. showed antigenic activity by immuno blotting technique. In sandwich ELISA technique eventhough all SDS-PAGE fractions except ESA 6 (55-47 kDa) showed antigenic positivity, the fractions ESA 8 (37-31 kDa) and ESA 9 (31-25 kDa) showed high reciprocal antigen titre of 262144 and 32768 respectively. In B. malayi infective larval ES products, the protein molecules of 109, 102, 97 and 77 kDa molecular wt. showed reactivity with FSIgG by blotting technique, where as in sandwich ELISA except ESA 7 (47-37kDa), all fractions showed antigenic positivity. However, these fractions failed to show high antigen titre similar to W. bancrofti ES products with FSIgG.