Location of a S. mansoni circulating antigen using indirect immunofluorescent assay

Indirect immunofluorescent technique was utilized to determine the location of butanol extracted microsomal antigen of adult S. mansoni. Bright fluorescence was located deep in the gut of both adult S. mansoni and S. haematobium treated with specific IgM monclonal antibody. No fluorescence was observed in any part of schistosomulae. Thus, this butanol extracted antigen may be considered stage and genus specific. The large surface area of the gut promises that enough antigen escapes to be detectable in the circulation of the host. This antigen has the potentiality to be used as a circulating antigen for diagnosis of active Schistosoma infection.