Fig. 1. Acquisition of heparanase activity by primary human fibroblasts. Human foreskin fibroblasts were incubated for two hours in the absence () or the presence of 10 µg/ml recombinant 65 kDa heparanase for 30 (), 60 () and 120 () minutes. Cells (2.5x10⁶ cells/ml) were then washed and incubated (4 hours, 37°C, pH 6.6) with sulfate-labeled ECM. Labeled degradation fragments released into the incubation medium were analyzed by gel filtration over Sepharose 6B as described in the Materials and Methods.