[Studies on the quality of enzyme preparations (X)--urokinase preparation]

Urokinase preparations were investigated with a view to comparing their quality by enzymological methods. These studies were carried out on 10 kinds (9 kinds of preparations produced from human urine and one kind of preparation produced from tissue culture) of commercially available urokinase preparations. The potency of all preparations assayed by the two-stage method were found to be within the range of permissible content. Because there are two molecular weight types (molecular weight: 54,000 and 33,000) of urokinase. the distribution of two types of urokinase in preparations was determined. Human urine urokinase preparations contained mainly the high molecular weight type urokinase (over 90%), and the tissue culture preparation contained the low molecular weight type urokinase alone.