Electron microscopy of isolated human hepatocytes

Summary We have investigated, by scanning and transmission electron microscopy (SEM and TEM), the cell surface morphology of isolated human hepatocytes. For this purpose, liver cells were mechanically isolated from surgical or needle liver biopsies, fixed in 3% glutaraldehyde and post-fixed in 2% osmium tetroxide. In order to handle a low number of cells, a particular procedure for harvesting hepatocytes on coverslips has been developed for SEM and anin situ embedding procedure in polyethylene-embedding capsules was applied for TEM. A rough membrane exhibiting short, uniform microvilli and pores of 0.1 μ in diameter was the main feature of isolated liver cells. Furthermore, single hepatocytes showed no polarity and junctional or bile canaliculus remnants were rarely observed. However, differences in surface configuration were noted in relation to culture conditions, such as oxygen and temperature during isolation procedures. SEM, when controlled by TEM for intracellular preservation, is proposed as a reliable method for screening small quantities of hepatocyte suspensions, for intact cells and for the study of surface configuration under experimental conditions. Part of this work was made possible by a grant from the Swiss National Science Foundation (grant no. 3.849.081), Dr. A. Trevisan is a recipient of a grant fromConsiglio Nazionale delle Ricerche (CNR), Roma, Italy, for research on viral hepatitis.