Isolation and purification of immunoglobulin G from bovine colostrums by hydrophobic charge-induction chromatography

Hydrophobic charge-induction chromatography, a novel chromatographic technique for bioseparation, was developed to isolate and purify bovine IgG with high purity. In this work, the raw IgG solution, a precipitate from bovine colostrum powder solution with 40% (wt/vol) ammonium sulfate, was dissolved in 50mM phosphate buffer and used as loading solution for investigating chromatographic conditions on a mercapto-ethyl-pyridine (MEP) HyperCel (Pall Corp., Port Washington, NY) sorbent. The initial IgG concentration had no effect on the dynamic binding capacity of MEP HyperCel resin, but the linear velocity of loading solution had an obvious effect on the dynamic IgG binding capacity and IgG recovery. The maximum linear velocity was optimized as 0.4cm/min of loading solution, and 90% recovery of IgG was achieved. Under these optimized binding conditions, the pH and ionic strength for the elution process were selected as pH 4.5 and 0.5 M NaCl, respectively. Subsequently, hydrophobic charge-induction chromatography was performed on a MEP HyperCel sorbent to isolate IgG using bovine colostrum whey as the loading solution. Under the optimized operation conditions, a remarkable process improvement in IgG purification was received, which includes a yield of 91.5%, a purity of 93.9% (wt/wt), and a purification factor of 6.8. The results indicated that MEP HyperCel chromatography offers an efficient means to purify IgG from bovine colostrums.