SCHISTOSOMA-MANSONI ANTIBODIES IN TISSUE SPECIMENS DEMONSTRATED BY A DIFFUSION-IN-GEL ELISA TECHNIQUE

A modification of the diffusion-in-gel enzyme-linked immunosorbent assay (DIG-ELISA) for analysis of antibodies in tissue fragments has been elaborated. In this technique, tissue specimens are placed on top of a thin gel layer covering a plastic surface coated with an antigen preparation. The gel thus serves as a medium through which diffusion of antibodies contained in tissue samples may occur. Specimens from skin, lung, liver, kidney, heart and skeletal muscle as well as blood serum and blood sampled onto filter paper were successfully used for analysis of the antibody response to two different antigens (soluble adult worm antigen and soluble egg antigen) during experimental infection of mice with the helminth parasite Schistosoma mansoni. It was concluded that skin and lung tissue reflected the serum antibody response more closely than the other tissues tested, although zone sizes were slightly smaller than those registered for corresponding serum samples. The DIG-ELISA reaction zone size was, as expected, shown to be dependent on the weight (size) of the tissue specimen. The variability of the modified technique was comparable to that found for analysis of serum by the conventional DIG-ELISA technique. It is concluded that the described technique may be used for serological analysis when blood samples cannot be easily obtained, e.g. at examination of animal carcasses or single organs.