A comparative analysis on serum antibody levels of sheep immunized with crude and thiol-purified excretory/secretory antigen of Haemonchus contortus

In vitro culture of live adult worms were made in RPMI 1640 medium at a concentration of approximately 50 worms / ml in a 0 culture flask at 37 C for 24 hours and the culture supernatant was used as antigen. The E/S antigen was purified by thiol – sepharose affinity chromatography. On western blot analysis, it was demonstrated that the crude E/S antigen showed five reactive bands at 24, 29, 46, 66 and 93 kDa and the Thiol – purified antigen showed a single reactive band at 66 kDa. In immunization trial, sheep were immunized with 500 μg of crude and thiol – purified E/S antigen along with montanide as adjuvant on day 0,30 and 60 intramuscularly. Further, the assessment of serum antibody levels in immunized sheep was made at weekly intervals by enzyme linked immuno sorbent assay (ELISA). It was observed that the mean absorbance values were significantly (P<0.01) higher up to 20 weeks post immunization in Group-I (purified antigen) than Group-II (crude antigen) compared to unimmunized control group.