Do I have to supplement the purified collagenase with a protease source?

Yes.  VitaCyte’s collagenase products are chromatographically purified.  The steps utilized in the purification process remove the protease activity that is normally present in the crude and enriched collagenase products from other vendors.  Since collagenases have a high specificity for collagen, a general protease activity is also required to degrade other extracellular matrix proteins and to accelerate the breakdown of the collagen fibrils.