Isolation and long term preservation of pancreatic islets from mouse, rat and guinea pig

This paper reports techniques for the isolation and long term preservation of pancreatic islets from the mouse, rat and guinea pig. Islets have been isolated using a modification of a free hand microdisection procedure described by Hellerström in 1964 [1]. Isolated islets have been subjected to three preservation systems and their viability following storage assessed by light microscopy of sections stained with Gomor's aldehyde fuchsin [2] and by measuring the insulin release from islets in vitro in response to a glucose stimulus. The systems were: a) Simple cold storage in Hank's balanced salt solution at 4 degrees C. Following 15 h cold storage, histological and functional survival was 100%. This dropped to 10% at 48 h. There were no survivors following 72 h storage. b) Sub zero cell storage. In Group I (freezing rate 1 degrees C/min) histological survival was 35% and functional survival 20%. In Group II (freezing rate 5 degreees C/min with 24 h culture period after rewarming) histological survival was approximately 87% and functional survival 75%. c) Organ Culture. Islets from the guinea pig, rat and mouse showed minimal morphologic damage when cultured for 21 days in a simple organ culture system. At 28 days, histological survial was approximately 30%. Following organ culture we were unable to correlate histological and functional survival.