Disaggregated gamma globulin and process for preparing it

Claim 1

The process for preparing a human gamma globulin disaggregated into sub-units by enzymatic action and having no significant effect on the complement system, which process comprises (1) treating a crude antibody-containing gamma globulin fraction of human serum, obtained by precipitating blood serum with ammonium sulfate or alcohol, at a pH between 3.5 and 5 and at a temperature from 25°C. to 45°C. with from 50,000 MTU to 100,000 MTU of pepsin per 100 grams of protein to be degraded, while continually controlling the anticomplement activity, for a period ranging from 12 to 48 hours, until the anti-complement activity, measured by combining a 1 ml sample of the disaggregated gamma globulin with 1 ml of a solution containing 100 units of guinea pig complement in the presence of a buffer solution and heating for 1 hour at 30°C., is such that more than 20 units of the complement in the original complement solution must not be inactivated; (2) removing low molecular weight decomposition products from the disaggregated gamma globulin by filtration; and (3) filtering the disaggregated gamma globulin under sterile conditions.