Abstract: A method of the production of immunoglobulin having a high content of monr from immunoglobulin-containing materials by a fractionation method, which comprises carrying out the fractionation in the presence of a water-soluble, basic nitrogen-containing organic compound having a dissociation constant (pKb) of 7 or less or an acid addition salt thereof, and thereby inhibiting by-production of undesirable aggregated molecules. The immunoglobulin has a high content of monomer and contains no or little aggregated molecules and hence can be used as a medicine in immune prophylaxis and immunotherapy without undesirable side effects and can be administered by intraveneous route, and further, is useful for the preparation of chemically treated immunoglobulin having a high content of monomer.

Abstract: Process for the production of a highly purified S-sulfonated gammaglobulin by treating an S-sulfonated gammaglobulin obtained by sulfonating a conventional gammaglobulin with an ion exchanger in a buffer solution for development, and thereby absorbing single molecular S-sulfonated gammaglobulin thereto, and eluting the single molecular S-sulfonated gammaglobulin with a buffer solution for elution. This process can give the desired S-sulfonated gammaglobulin having a high content of single molecule and an extremely small anticomplementary activity (e.g. CH.sub.50 of 10% or less) and also an excellent shaking stability from the conventional gammaglobulin in an industrial scale.