Preparation of Lnsulin-like Growth Factor-1 from Bovine Colostrums

摘要

This experiment achieved a purpose that bovine colostrums IGF-1 were extracted from bovine colostrums rapidly and efficiently. Fresh bovine colostrums were heated at 40°C for 1h and centrifuged at 2500 rpm for 20min, then they were discarded the upper fat and adjusted the pH value of skim milk at 4.2 to remove casein, the salting saturation was 35% to remove high molecular proteins. We extracted IGF-1 concentrated liquid by the ultra filtration which were 50ku and 3ku molecular weight, and the IGF-1 concentrated liquid were purified further by chromatography which was filled up weak cation exchanger (CM-SephadexC-25), the equilibrium buffer was NaCl solution (0.02 mol/L buffer, pH 7.25, the flow rate was 80cm/h). Finally we used the HPLC and the ELISA to determine the purity and the yield of the IGF-1 concentrated liquid. The results were that the yield of the bovine colostrums IGF-1 was 71.98%, and the purity was 65.51%.