Evaluation of a crude soluble antigen from in-vitro culture of Plasmodium falciparum for ELISA

Abstract

The present study was to evaluate the soluble antigen prepared from the in-vitro cultured P. falciparum (FCR3) as an alternative source of antigen to those obtained from in-vivo models for enzyme linked immunosorbent assay (ELISA) in serology of malaria. Results obtained on known positive and negative reference sera revealed good correlation between the ELISA and the indirect fluorescent antibody (IFA) technique (rs = 0.797; p less than 0.001). However such close correlation was not observed on six local sera from patients whose peripheral blood smear showed ring stage of P. falciparum (rs = 0.43; p greater than 0.05), though all the six sera were positive by the IFA and ELISA tests. Test was repeated to establish its reproducibility. The results indicate that antigen prepared from in vitro culture and stored in liquid nitrogen was found sensitive in ELISA for serology of malaria.