A high yield of viable single cells was attained from isolated pancreatic islets of adult rat by the sequential treatment with EDTA and Dispase. The percentage of single cells was consistently higher with EDTA-Dispase in comparison with EDTAtrypsin treatment, being 65.8±7.9% and 36.0±5.4% respectively, when more than 90% of total islet cells were viable. Excellent preservation of free islet cells dissociated with EDTA-Dispase was demonstrated morphologically by light and electron microscopy.
The secretory response of dissociated B cells to glucose was stabilized earlier with EDTA-Dispase than with EDTA-trypsin treatment. The amount of insulin released into the medium was proportional to the number of cells inoculated, thus permitting the quantitative analysis of B-cell function in vitro.