The First Reference Preparation of urokinase was released in 1968 with a specified activity in an ampoule. It was prepared from human urine.
There is a low molecular weight (30,000 daltons) and high molecular weight (50,000 dalton) proteins, each type a disulfide-linked dimmer.
6.77 mg of urokinase = 4,800 International Units (IU)
1 mg = 709 IU
1 IU = 0.00141 mg
