Abstract: The purpose of this experiment was to explore the influence of the sample loading volume,flow rate and protein concentration of protein on the removal efficiency of endotoxin and protein loss in porcine visfatin recombinant lipoprotein solution at 4 ℃.In this study,commercial and modified polymyxin B was used as the medium to specifically remove endotoxin from the protein solution.At 4 ℃,different loading volume (6,8,10,12 mL),flow rate (0.125-0.75 mL/min) and protein concentration (0.9,1.2,1.3,1.7 mg/mL) were used for endotoxin removal,the content of endotoxin was determined by a quantitative method using endotoxin reagents,and the BCA protein concentration assay kit was used to determine the protein concentration.The results showed that at 4 ℃ endotoxin removal was the best when protein loading volume was 12 mL and flow rate was 0.125-0.25 mL/min,the removal rate was 99.5%,the residual amount of endotoxin (1 EU/mL) was within the biosafety range,and the protein recovery rate was as high as 90% to 95%.The experimental results showed that the endotoxin was successfully removed from the solution of porcine lipin recombinant protein,which provided references for the related functional research and clinical application of the protein.

Key words: swine visfatin recombinant lipoprotein solution; endotoxin; removal conditions; removal rate; recovery rate