To determine the optimal storage solution containing suitable protective agents for the preservation of microencapsulated hepatocytes at 4 A degrees C as well as the optimum incubation time after hypothermic preservation. L15 was the optimum solution for both maintaining microcapsule integrity and cell viability. Furthermore, 5 %(v/v) PEG (20 or 35 kDa) added to Leibovitz-15 medium was optimal for microencapsulated C3A cells, enhancing cell viability and liver-specific functions, including albumin and urea synthesis as well as CYP1A2 and CYP3A4 activities. The transcription levels of several CYP450-related genes were also dramatically increased in cells incubated in the optimal solution. Pre-incubation for 2 h was the optimal time for restoring favorable levels of CYP1A2 and CYP3A4 activities in microencapsulated C3A cells for short term, 2 day storage. Leibovitz-15 medium supplemented with 5 % (v/v) PEG is a promising cold solution for microencapsulated hepatocytes at 4 A degrees C, with an incubation of 2 h at 37 A degrees C after hypothermic preservation being the best incubation duration for further cell application.