author(s)
Anjali Tomar, Ranjit Aich, Daljeet Chhabra, Vivek Agrawal and Ajit Pratap Singh

abstract
Haemonchus contortus releases certain excretory-secretory (E/S) proteins which are essential for their survival inside the host and can perform functions like tissue penetration and host protein degradation. The present study was carried out with an aim of immunochemical characterization of E/S proteins of H. contortus isolated from goats. The E/S proteins were isolated by in vitro cultivation of H. contortus in RPMI 1640 medium. Fractionation of whole E/S antigen was done by SDS-PAGE (12.5%) which revealed the presence of five (24, 55, 62, 66 and 93 kDa) polypeptide bands. The purification of whole E/S antigen was done by gel filtration chromatography using Sephacryl S-200. Purified fraction of E/S antigen revealed two (24 and 66 kDa) polypeptide bands in SDS-PAGE (12.5%). Both these polypeptides were found immunodominant with hyperimmune sera (raised in rabbit) on western blot analysis. Antigenicity of purified E/S antigen was determined by indirect ELISA and the titer was 800-1600. It suggested that the purified E/S proteins have retained enough antigenicity during purification process which may be used as potential vaccine candidates as well as for development of user-friendly, cost effective diagnostic technique like dip-stick ELISA for serodiagnosis of haemonchosis in goats.