[A simple method for the separation and purification of the surface antigen of hepatitis B from serum (author's...

The present report describes a simple, rapid and reproducible procedure for preparation of hepatitis B surface antigen from human positive sera, with a satisfactory yield. After removal of beta- and alpha-lipoproteins by dextran sulphate precipitation and subsequent removal of IgM and a part of the other serum proteins by dialysis against distilled water, the supernatant obtained presents almost no change in its surface antigen content. After passing this solution through a molecular sieve of Biogel A-5 m, the surface antigen is detected in a well-defined peak. The fraction correspinding to this peak is collected in its totality. After lyophilization, it is passed through a molecular sieve of CPG 10, in phosphate buffer; this allows recovery of a substance which has retained its structural as well as its antigenic properties, and which is intact and practically free of any serum contamination.