Urokinase is an enzyme protein isolated from the urine of healthy people or obtained from human kidney tissue culture. It is composed of protein with molecular weight of 33000 mg and 54000 mg, respectively. This product direct effects on endogenous fibrinolysis system, which can catalytic cracking fibrinolytic enzyme into a fibrinolytic enzyme, which can not only degradation of fibrin clot, also can degrade fibrinogen in blood, and clotting factor Ⅴ and blood coagulation factor Ⅷ etc, so as to play a role of thrombolysis.

　　Methods of urokinase extraction:

　　1. Fill the pail with urine and store it in a cool place. Adjust the PH of urine to below 6.5. In summer, the urine is easy to go bad, so 0.8 phenol is added to prevent wei. Each collection of urine should be disposed of within 8 hours.

　　2. Precipitation treatment: keep the urine below 10℃, adjust the PH value to 8.5 with sodium hydroxide, mix it evenly, let it stand for L hours, after precipitation, siphon out the supernatant with rubber tube, and acidify it to the PH value of 5-5.5.

　　3. Adsorption of diatomite. According to the proportion of urine volume L after acidification, pre-cleaned diatomite was added and adsorbed at 5℃ for several hours.

　　4. The elution. The diatomite adsorbents are washed once in 5℃ cold water, and then loaded into the diatomite column (column ratio 1). 1) Wash with 0.02% ammonia to make the washing liquid clear from muddy, then wash immediately with 0.02 ammonia and 0.1m sodium chloride solution. Urokinases are collected when the water from the diatomite column is muddied.