Long-term culture of isolated pancreatic islet cells.

Successful long-term culture of isolated pancreatic islet as well as dissociated islet cells was accomplished with the use of Microtest II trays which provides the very small amount of culture medium that is easily conditioned. In the culture of isolated islet, the ultrastructure of the islet cells was completely preserved up to the 30th day and vigorous secretion of insulin was maintained even on the 75th day. While in the islet cell culture, insulin secretion gradually decreased from the 12th day. The latter procedure makes inoculation of a definite number of dissociated pure islet cells possible, thus opeing the way to the quantitative evaluation of B cell function in vitro.