Cryopreservation of precision-cut rat liver slices using a computer-controlled freezer

Precision-cut liver slices are frequently used to study hepatic toxicity an d metabolism of xenobiotics in vitro. Successful cryopreservation technique s will enhance an efficient and economic use of scarcely available (human) liver tissue. For primary hepatocytes, slow freezing has been accepted as t he best approach towards successful cryopreservation. For slices, however, no agreement exists on the optimal way of cryopreservation and both slow an d fast freezing techniques have been reported. The aim of the present study was to determine the applicability of a computer-controlled slow freezing technique for the cryopreservation of (rat) liver slices. Thus far, this te chnique has not been described in detail. Our studies confirmed that slow f reezing was most successful in the cryopreservation of primary rat hepatocy tes. Based on this observation, the slow freezing technique was applied to the cryopreservation of rat liver slices. Directly after thawing, slice via bility was between 60 and 100% of fresh values, depending on the parameter determined. However, after additional culturing, slice viability was reduce d. This decrease in slice viability was more pronounced in comparison to pr imary hepatocytes. In conclusion, the slow freezing technique was confirmed to be a successful approach for the cryopreservation of primary rat hepato cytes, and was found to be of limited use for the cryopreservation of rat l iver slices. (C) 2000 Elsevier Science Ltd. All rights reserved.