Urokinase produced by cultured human kidney embryo cells

: Urokinase was obtained from cultured cells of human fetal kidneys. Ultrafiltration on an Amicon cell and purification by gel filtration chromatography (Ultrogel ACA54) yielded two molecules capable of activating plasminogen into plasmin. Their molecular weights were respectively 47,500 and 31,500 daltons. The first one showed more active than the latter. In this experiment, only small amounts of Urokinase were harvested. The yield could be enhanced using activators (pronase, glycine) or adapting fetal cells to large scale cultures.