Purification of hepatitis B surface antigen using polyethylene gylcol, pepsin and Tween 80

A simple, inexpensive procedure for the isolation and purification of HB8Ag from plasma is described. The technique included precipitation of HBsAg with PEG and elimination of normal plasma proteins by digestion with pepsin. Tween 80 was used to remove contaminating lipoprotein(s). This technique resulted in about a 200-fold gain in the specific activity of HBsAg and yielded about 20-40% recovery. Rabbits immunized with the purified antigen produced type-specific antibodies to HBsAg without detectable reactivity to normal human plasma antigens.