Use of dialyzed venoms in the radioallergosorbent test

Optimal concentrations of honeybee, hornet and yellow jacket venoms were used in the radioallergosorbent test (RAST) before and after dialysis. RAST titers in the majority of sera from insect-allergic patients increased significantly with the dialyzed yellow jacket and hornet venom-coupled discs. Of 26 sera which had negative RASTs with crude venom, 20 became positive with dialyzed venom. No change in RAST results was found with crude and dialyzed honeybee venom. The low molecular weight component in the vespid venoms removed by dialysis had no specific activity in RAST inhibition experiments, suggesting nonspecific blocking of binding sites. These results indicate the importance of the appropriate antigen preparation coupled to discs in the RAST.