Collagenase Type 4 contain lower tryptic activity levels to limit damage to membrane proteins and receptors but with normal to above normal collagenase activity. It is suggested for pancreatic islet primary isolation. Collagenase is typically used at concentrations from 0.05 % to 0.5 % (w/v) in balanced salt solutions such as Hank’s, Earle’s and others. For best results the precise mixture of collagenase and proteolytic activities must be tailored to the tissue to be dissociated. Specific conditions for reactivity should be optimized by the end user.