Application of commercial immuno assay (ELISA) technique for determination of hepatitis A antigen (HAV) in raw milk

The objective of this study was to detect HAV antigen in raw cow’s milk supplied in Mashhad, Iran using ELISA technique. To ascertain the best recovery method for detecting HAV antigen in raw milk, different dilutions of HAV antigen (0.00, 1.0, 10−3, 10−6 and 10−9 ml/l) were added to UHT milk. Results obtained from the recovery of HAV antigen from treated milk showed that milk with acidic coagulation followed by filtration with paper filters and membrane filters, had the most optical density and considered to be the best recovery method. Then, the detection of HAV in raw milk in two seasons spring and summer was investigated. HAV antigen was detected in 13.3% and 34.48% of milk samples of spring and summer, respectively.