Purification of Large Quantities of Australia Antigen by Density Gradient Centrifugation

In order to prepare specific, animal, anti-Australia immunoglobbulins on a large scale, we have attempted hepatitis-associated antigen (Au-SH) purification from human ascitic fluid, plasma, and sera, with a zonal rotor (MSE B XV), in sucrose gradients. Accepting the 110S sedimentation coefficient value, 1 the estimated centrifugation conditions did not provide a satisfactory separation of Au-SH from largest proteins. Considering this slow rate of zonal sedimentation, we estimated a value at most of 50S. New centrifugation conditions were calculated. The original materials are constituted of 100- to 500-ml batches of positive Au-SH serum undergoing several cycles of purification (18 hours; 25,000 rpm; 5 C on a 15% to 45% w/w sucrose gradient in phosphate Sorensen buffer, pH 7.5). Before each cycle, the Au-SH-positive fractions are filtered on membranes (Amicon PM 30) to provide 100 ml with a 1.03 280 nm 254 nm 10 15 20 EID + 35 Fig 1.—Findings on the