Suspension of hepatocytes was isolated from the livers of male Wistar rats weighing 200-250 g. by using the method of Berry and Friend as modified by Stacey and Priestly. Morphological features, plasma membrane integrity and metabolic capability were used as the criterion for cell viability. The successful method to obtain good cell preparations must involve three critical steps ; namely, exposure of the liver to a calcium free medium, digestion with collagenase in a recirculating system and gentle mechanical treatment. Albumin (1.2%) in the final medium which was used for suspending cells is necessary to maintain cell viability. Cell yields of 2-3 × 10 8 cells were obtained with a trypan blue exclusion index of 90-98%. Cell preparations with a trypan blue exclusion index of less than 90% were not recommended for any studies.
