Immunodiagnosis of cysticercosis: standardization of ELISA and its application to field conditions.

A standardization procedure for the enzyme-linked immunosorbent assay (ELISA) is described. Results were expressed as antibody units (ABU) which represent a multiple of absorbance of the negative control. The method was applied to immunodiagnosis of cysticercosis by IgG antibody determination. Different incubation temperatures had no substantial effect on results. There was a fair correlation between results obtained under field conditions in Cajamarca/Peru and results obtained under optimal laboratory conditions in Hamburg/FRG. Activity of antigen that had been lyophilized and stored under vacuum at ambient temperature was similar to the activity of antigen that had been stored frozen. There was a considerable loss of activity when antigen had been adsorbed to microtitre plates which were then stored in evacuated plastic bags at room temperature. Reproducible results were obtained both under optimal laboratory conditions and in the field.