Collagenase B, Animal Component-Free (ACF) is obtained from cultures free of animal-derived materials. Collagenase is a protease consisting of a single polypeptide chain approximately 1,000 amino acid residues in length. Collagenase is capable of digesting native collagen fibrils commonly found in connective tissues and therefore is frequently used for tissue dissociation. Collagenase preparations contain the activity of several proteases, including collagenase, caseinase, clostripain, and trypsin (Kessler & Yaron). Collagenase B, ACF contains higher collagenase and caseinase levels than Collagenase A and is intended for use in applications where it is necessary to prevent the introduction of potential animal-derived pathogens.