Degrade protein substrates effectively while minimizing cell damage with Papain. This cysteine protease has a wide specificity, but has a preference for arginine, lysine, and phenylalanine. Native crystalline papain is unreactive until acted upon by mild reducing agents, e.g., cysteine, sulfide, or sulfite, and therefore likely exists as a zymogen. Compared to other pancreatic proteases, this enzyme facilitates more extensive degradation of protein substrates, such as the intercellular matrix proteins in cartilage. It is typically less damaging and more effective than other proteases for tissue dissociation applications (Huettner & Baugham; Lam). Papain has also been used for the digestion of neural tissue (Fasano et al.).