Estimation of cercarial antigen efficiency by enzyme-linked immunosorbent assay (ELISA)

Cercariae were collected, hemogenized and the amount of protein was measured. ELISA was preformed by using 3 concentrations of cercarial Ag(2.5 ug/ml; 5 ug/ml and 10 ug/ml) also two types of sera were used; immune and non immune. Two dilutions (1:500 and 1:2000) of the conjugate were used in this test. The degree of absorbance was measured after 24 H by spectrophotometer, where the results showed that, the degree of absorbance was increased in the presence of immune sera and also in the presence of 1:500 conjugate concentration, but there was no difference in the degree of absorbance with the use of different Ag concentrations. It is obvious that 2.5 ug/ml of Ag could give very high ELISA readings with infected mice sera.