Isolation and antigenicity evaluation of β-lactoglobulin from buffalo milk

Buffalo β-lactoglobulin in phosphate buffer (0.02 M, pH6.8) was adsorbed on DEAE-Sepharose Fast Flow gel, and eluted with a linear gradient of NaCl (0-0.5 M) in 0.02 M phosphate buffer, pH 6.8. A further purification was performed on Sephadex G-75 gel by loading a concentrated and dialyzed fraction of samples containing buffalo β-lactoglobulin from ion-exchange chromatography, and seperating at a flow rate of 0.15 ml/min in 0.02 M phosphate buffer, pH 6.8. The purity of the isolated buffalo β-lactoglobulin was above 90% in comparison to the standard bovine β-lactoglobulin by SDS-PAGE and IEF-PAGE. The antigencity of the buffalo β-lactoglobulin was evualuted by indirect ELISA, Westernblotting and inhibition ELISA with anti-buffalo and anti-bovine β-lactoglobulin rabbit serum. The results showed that buffalo β-lactoglobulin could be seperated and purified by anion-exchange chromatography combined with gel filtration chromatography, and with a well-preserved antigenicity.