Summary
A method is described for direct observation of the fibrinolytic activity in tissue cultures. The method consists in placing in the culture system a small glass tube open at one end and filled with fibrin. In the presence of fibrinolytically active expiants fibrin dissolves progressively from the free end of the tube, and can be measured directly. Direct observation and the recording of the lysis is a simple and precise method for studying the fibrinolytic activity of tissue cultures.