ADVANTAGES OF USING A CELL SEPARATOR AND METRIZAMIDE GRADIENTS FOR HUMAN ISLET PURIFICATION

Human islet transplantation has a high rate of failure, often due to p rimary nonfunction, which suggests that islets are damaged during the processing of the pancreas. The preparation of human islets for transp lantation is still a complex process that requires large teams of surg ical and laboratory personnel, To overcome this problem, we have adopt ed the use of the IBM 2991 COBE cell separator and a metrizamide/Ficol l density medium that is easy to prepare, Twenty-seven pancreatic glan ds have been processed using the COBE cell separator, 23 of which were purified in metrizamide/Ficoll gradients and 4 in bovine serum albumi n gradients, The results show an improvement of recovery and viability in these preparations when compared retrospectively with manual gradi ents, More importantly, the time required for purification was shorten ed to one fourth the usual time and total processing time is about hal f as long. Moreover, a team of two laboratory staff was regularly able to prepare islets for transplantation, reducing the separation time f rom 7 hr to 3.5 hr, We conclude that the automatic cell separator and metrizamide-based separation medium are useful modifications of curren t islet purification methods.