Direct separation and purification of hemoglobin from fresh bovine hemolysate were studied with expanded bed adsorption. Ionic strength

pH and temperature had great influence on the formation of methemoglobin in the process. The purity and recovery of the product were also influenced by these factors. The conditions for adsorption and elution were optimized. The best performance was obtained by using 10mmol8226;L-1 phosphate buffer solution

pH6.6. Eluting at pH 7.2 was carried out at low ionic strength and the final recovery of hemoglobin was more than 80%. A low temperature of 4℃ in the process was necessary for prevention of methemoglobin formation. Under optimized conditions

natural bovine hemoglobin of electrophoretical purity could be obtained by only one step of operation

and the dynamic adsorption capacity was between 70—75mg8226;ml-1. HPLC result suggested that the purity of the product was about 99%.Methemoglobin was kept as low as 5.4%. Compared with the traditional process of membrane filtration followed by chromatography

the expanded bed adsorption has the advantages of short processing time

high recovery

and high product activity. The method was simple

efficient and potential scale-up to commercial production.