[Isolation and purification of islets in non-obese diabetic mice].

OBJECTIVE: To investigate the method of isolating and purifying islets in non-obese diabetic (NOD) mice. METHODS: The isolation of adult NOD mice pancreatic islets was carried out by stationary digestion after pancreatic ductal injection of collagenase solution. A discontinuous Ficoll solution (25%, 23%, 20.5%, 11%) was applied to the purification of the islets. The specificity of the islets was determined by dithizone(DTZ) staining, and the function was evaluated by the glucose stimulating insulin releasing test. RESULTS: The yield and activity of the islets varied with different concentration collagenase and digesting times. After incubation of the pancreas with 1.0 mg.ml-1 Type XI collagenase for 40 min, each pancreas could yield (195 +/- 8) islets, with viability > 90% and purity > 90%. The islets were red and intact after DTZ staining. The insulin from the islets fed with high concentration glucose was 2 times that with low concentration. CONCLUSION: The modified method of pancreatic ductal collagenase injection, followed by stationary digestion and purification of islets with a discontinuous Ficoll solution, can reproducibly yield various and pure islets.