Fig. 1.

Primary culture of adult C57BL/6 mouse hepatocytes and the proliferation of Kupffer cells. After 2 days of culture, hepatocytes spread onto the surface of the culture flasks and displayed a typical polygonal cobblestone-like morphology. Hepatocytes that lost their epithelial cell morphology after 4 days in culture changed into more flattened, fibroblastic cells. Around days 7–10, phase contrast-bright, round Kupffer-like cells started to proliferate on the fibroblastic cell sheet (arrowheads). The proliferation of Kupffer cells continued and reached a maximum on day 10 and continued thereafter. Scale bar = 100 µm.