Fig. 4. In vivo fate of progenitor liver cells. Eighth passage cells are shown 3 weeks after transplantation into the peritoneal cavity. (A) Confluent mass of transplanted cells adjacent to microcarrier bead (m), with typical hepatocyte morphology (H&E stain). (B) In situ hybridization of contiguous sections with human DNA probe visualized cell nuclei, whereas negative control tissues, where the probe was omitted, showed no signal (C). Transplanted cells contained G-6-P (D), glycogen (E), -1 microglobulin (F) and albumin (G). The arrow in E points toward glycogen granules. (H) shows electron micrography of transplanted cells adhering to a microcarrier bead (m). The cells display epithelial morphology with microvilli on the apical surface (arrow) plus nuclei, nucleolus, abundant mitochondria and bile canaliculi (bc), which are ypical of hepatocytes (original magnification x2,500).