| Immobilized metal affinity membrane is a effective technology for isolating protein. In this paper, the feasibility of the cotton fabric as the membrane matrix is studied. Affinity membrane was successfully prepared with cotton fabric as support by epoxy activation, and the process, adsorption of proteins and purification of proteins were studied.The best carrier was 100% cotton fabric selected from five fabrics with different cotton content. The stability experiment shows that the membrane can store in 20% ethanol, air, distill water and the copper ion content is invariable. The affinity membrane could be reusable.The best conditions were obtained through the single factor and orthogonal experiments. The optimal condition for the activation reaction was 2.0mol/L NaOH at 30℃for 4h.The optimum condition for IDA linkage was in 15mL of 1.5mol/L Na2CO3 containing 1.2g IDA, at 50℃for 10h. The shaking rate was 155rpm.The lysozyme adsorption on the affinity membrane reached adsorption equilibrium after about 1h. The equilibrium adsorption capacity of lysozyme increased with increasing temperature, but the ionic strength was reverse. The maximum lysozyme adsorption was obtained at pH 7.0; the equilibrium adsorption increased with increasing the concentration of lysozyme in the adsorption medium until reached adsorption saturation. The isothermal adsorption for lysozyme could be expressed by the Langmuir adsorption model, and the most adsorption capacity of affinity membrane was 0.50mg/cm2 membrane.The column was prepared stuffing affinity membrane with cotton fabric as support. The sampling flow-rate, washing flow-rate and elution flow-rate were 0.8mL/min,1.6mL/min,2.0mL/min. The egg white and whey protein were chosen as studying the capability of immobilized metal affinity membrane with cotton fabric as carrier. The high purity lysozyme were obtained by only one step using this membrane. The separate effect of whey protein was not evidence, casein was maybe adsorbed.
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