title: Serva collagenase NB1: a new enzyme preparation for human islet isolation.
abstract: BACKGROUND
  Advances in the rate of success of human islet isolation are due in part to the availability of new purified enzyme blends. In this study we evaluated a new enzyme preparation composed of a highly purified collagenase that can be reproducibly blended with predetermined amounts of separately packaged neutral protease.
  
  
  METHODS
  Nine human islet isolations were performed with collagenase NB1 supplemented with neutral protease (Serva Electrophoresis GMbH, group I). Yields, purity, morphology, in vitro function and islet cell apoptosis were assessed. The results were compared to those of nine human islet isolations performed with Liberase (Roche, group II) and matched for donor age, BMI, and circumstances of death.
  
  
  RESULTS
  Islet yields were similar in both groups. However, islet equivalents (IE) per gram of pancreas and IE number to islet number were higher in group I (P <.05). Stimulation indices after insulin response to glucose (static incubation) were similar in both groups. Islet cell apoptosis rate was statistically significantly lower in group I. Islet morphology was significantly improved in group I with a higher proportion of intact islets.
  
  
  CONCLUSIONS
  This new enzyme preparation (collagenase NB1 with neutral protease adjunct) was as effective as Liberase in terms of islet yields and function. Islet morphology was improved and rate of islet cell apoptosis was lower with this new collagenase. The absence of lot-to-lot variability in terms of neutral protease to collagenase ratio makes collagenase NB1 a promising enzyme for human islet isolation.
authors.affiliation: Department of Surgery, Cell Isolation and Transplantation Center, Geneva University Hospital, Geneva, Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Bucher
authors.forename: Z
authors.initials: Z
authors.lastname: Mathe
authors.forename: D
authors.initials: D
authors.lastname: Bosco
authors.forename: A
authors.initials: A
authors.lastname: Andres
authors.forename: M
authors.initials: M
authors.lastname: Kurfuerst
authors.forename: N
authors.initials: N
authors.lastname: Rämsch-Günther
authors.forename: L
authors.initials: L
authors.lastname: Buhler
authors.forename: Ph
authors.initials: P
authors.lastname: Morel
authors.forename: T
authors.initials: T
authors.lastname: Berney
mesh_terms: D015992:Body Mass Index; D002469:Cell Separation / Q000379:methods; D017364:Collagenases; D006801:Humans; D007515:Islets of Langerhans / Q000166:cytology*; D010447:Peptide Hydrolases
chemical_list: D010447:Peptide Hydrolases; D017364:Collagenases