Plasininogen Purification by Acid Extraction

The procedures described above utilize a previously undescribed property of plasminogen, solubility in dilute mineral acid, to extract it from placental and plasma fractions. Purification of over 250-fold has been obtained by successive extractions with 0.2N H2SO4 and precipitations at pH 5.2. The total yield has ranged from a minimum of about 10% to almost complete recovery of the enzyme present in the starting material, with an average recovery of about 30%.