Purified Tissue Dissociation Enzymes: Past, Present, Future Challenges

The incorporation of purified neutral protease and class I & class II collagenase isolated from C. histolyticum culture supernatants into defined tissue dissociation enzyme (TDE) mixtures was in part responsible for the success of the Edmonton protocol. The enzyme composition of Liberase HI Purified Enzyme Blend (HI) was determined by using design of experiment methodology to optimize the concentrations of neutral protease and collagenase required to maximize recovery of islets from human pancreata. Additional benefits from this approach were reproducible preparation of TDE products, increased shelf life, and dramatic reduction in endotoxin contamination. In early reports, purified TDEs gave significantly higher islet yields than those obtained after tissue digestion with crude collagenase products.