A simple quantitative assay of tissue plasminogen activator.

A simple method for the quantitative assay of tissue plasminogen activator is described. Human veins and uterus obtained at operation are disintegrated in a membrane disintegrator at -70 degrees C and a known weight of the powder, suspended in buffered saline and thoroughly mixed. Assay of the dilutions of this homogenate on isotope-labelled fibrin clots gives straight line plots of log weight against log activity of the dilution and the sample activity is calculated from this. The method has been compared with the conventional histochemical technique. A highly significant correlation between the results of the two methods has been obtained (r = 0.79; p less than 0.001).