title: Multi-lot analysis of custom collagenase enzyme blend in human islet isolations.
abstract: BACKGROUND
  Variability currently in Liberase HI from lot to lot limits the ability to effectively isolate islets with consistency. Roche Diagnostics Inc (Indianapolis, Ind, USA) has developed a Custom Collagenase enzyme blend in hopes that producing collagenase II and I and thermolysin separately will eliminate variability. In this study we examined the variability in Custom Collagenase lots in respect to isolation results and isolation success rates and compared those to Liberase HI.
  
  
  METHODS
  We retrospectively analyzed records from 68 islet isolations where either Liberase HI (lot A: n = 23, Lot B: n = 20) or Custom Collagenase blend (Lot C: n = 10, Lot D: n = 15) was employed. Human islets were isolated from cadaveric pancreata using standardized methods performed in a controlled islet isolation facility.
  
  
  RESULTS
  Analysis of Liberase HI and Custom Collagenase using Student t test showed no difference between the two groups. Comparison of the two Custom Collagenase lots using the t test showed a statistical difference between undigested pancreas weight and pancreas digestion times. Using chi-square test, no statistical significance was found in isolation success rates from lot to lot.
  
  
  CONCLUSIONS
  Although the Custom Collagenase blend is comparable to Liberase HI in its ability to isolate human islets, variability still exists from lot to lot when used conventionally as Liberase HI is. The ability to predetermine doses is beneficial, and as techniques to manipulate the activity levels prior to isolations improve so to will the enzymes' ability to isolate islets on a consistent basis.
authors.affiliation: Clinical Islet Transplant Program, Department of Transplant Services, University of Alberta Hospital, Edmonton, Alberta T6G 2N8, Canada.
authors.forename: D
authors.initials: D
authors.lastname: O'Gorman
authors.forename: T
authors.initials: T
authors.lastname: Kin
authors.forename: D
authors.initials: D
authors.lastname: McGhee-Wilson
authors.forename: A M J
authors.initials: AM
authors.lastname: Shapiro
authors.forename: J R T
authors.initials: JR
authors.lastname: Lakey
mesh_terms: D001926:Brain Death; D002469:Cell Separation; D017364:Collagenases; D006801:Humans; D007515:Islets of Langerhans / Q000166:cytology*; D012189:Retrospective Studies; D013820:Thermolysin; D020858:Tissue and Organ Harvesting / Q000379:methods
chemical_list: D017364:Collagenases; C106635:Liberase; D013820:Thermolysin