Improved islet isolation from rat pancreas using 35% bovine serum albumin in combination with Dextran gradient separation.

We have developed a gradient separation technique in which albumin-coated (35% BSA) rat islets are isolated in Dextran (BSA/D). Versus Dextran alone (DA), BSA/D increases mean islet yield from 850 +/- 115 to 1222 +/- 210 islets/donor (mean +/- SD, P=.001). With numbers of donors held constant, the time to euglycemia was significantly shorter in syngenic recipients of BSA/D than DA islets (5.7 +/- 4.8 versus 14.2 +/- 5.6 days, P=.02). However, when the number of islets were held constant, differences in time to cure were not statistically significantly different (P>.19): with 1200 islets, 3.8 +/- 2.8 (DSA/D) versus 9.2 +/- 8.2 (DA) days; with 750 islets, 18.3 +/- 5.8 (BSA/D) versus 18.0 +/- 4.5 (DA) days. In all groups, posttransplant day 1 glucose was lowest with the BSA/D technique. Thus BSA/D isolation gives a higher yield with at least equal viability. We recommend the BSA/D technique for its efficiency and economy.