EGG-WHITE LYSOZYME PURIFICATION BY ULTRAFILTRATION AND AFFINITY-CHROMATOGRAPHY

Isolation and purification of lysozyme from hen egg white was studied using a two-step procedure. The egg white was diluted 5- to 9-fold wit h sodium phosphate buffer, and then processed by sequential dilution d iafiltration using a UF membrane (molecular weight cut-off 300,000 dal ton). The membrane process increased the specific activity of lysozyme 6-fold, and recovered 96% of lysozyme activity. The permeate from dia filtration was further purified by affinity chromatography using chiti n as adsorbent. The second step of the process yielded a product of sp ecific activity of 70,400 units/mg protein. The overall lysozyme recov ery was 79%.