Figure 3. Photomicrographs show bromodeoxyuridine incorporation into hepatocytes after embolization. Bromodeoxyuridine was injected either 7 days after (A, B) or immediately after (C, D) embolization of the portal vein branches supplying the left and median lobes. Liver tissue from the right (nonembolized) lobe was collected 4 hours later, and bromodeoxyuridine incorporation into hepatocyte nuclei was assessed as described in Materials and Methods. A, C, No counterstain was applied, and the dark reaction product indicating DNA synthesis is seen only in the tissue obtained 7 days after the embolization procedure (A). B, D, The sections have been stained with hematoxylin to better visualize the nuclei of all the cells in the section. (Original magnification, x125.)