Cryopreservation of chick islets.

The avian endocrine pancreas shares some similarities with those of mammals. Previously we have reported a technique of isolation of B islets from chick pancreas and also demonstrated their possible use for hypoglycemic drug screening as efficiently as mammalian islets. Here we describe a novel cryopreservative medium for the cryopreservation of chick islets. Isolated chick islets were suspended in a cryo medium consisting of Dulbecco's modified Minimum Essential Medium: Ham's F12 (1:1), Fetal Bovine Serum (20%), Dimethylsulfoxide (10%) with different concentrations (50 microg/ml to 500 microg/ml) of riboflavin or nicotinamide. The viability of revived islets after three and half months was checked by trypan blue dye exclusion and functionality was assessed by insulin secretion in response to glucose challenge. The maximum recovery of viable islets and insulin secretion was obtained in response to glucose challenge at 250 microg/ml concentration of Riboflavin or Nicotinamide. This is a first report on cryopreservation of chick islets exhibiting cryoprotective role of water soluble vitamins without vitamin C.