Table 1.

Assays used to assess collagenase enzymatic activity Enzymatic assays

Assay	Ref.	Substrate	Isoform Bias	Collagenase		Advantages	Disadvantages
				Active	Inactive
Peptide activity	65,82	Pz peptide FALGPA	C2 >> C1	+	+	Reproducible Broadly used Sensitive Specific	Poor measure of C1 activity Cannot discriminate between intact or degraded C1 or C2
Azocoll	83,84	Dye impregnated cow hide	C2 ~ C1	+	+	Quantitative Linear	General protease substrate
Gelatinase	83	Gelatin	C1 > C2	+	+	Quantitative Linear	General protease substrate
CDA	20,68	Collagen fibers	C2 ~ C1	+	−	“Classical” Mandl assay used by some suppliers to characterize product	Non linear Poor precision Time consuming
CDA	66	FITC collagen fibers	C1 > C2 ~ C1b ~ C1c	+	−	Quantitative Linear Detects different molecular forms of C1	Fluorescent assay Specialized equipment