(a)
(b)
Figure 4: Analysis of gene expression in murine liver and hepatocytes after HGD-based gene delivery (a) and EP-based gene delivery (b). In (a), the liver is dissected 2 days after HGD with pT-EGFP, ptdTomato, and pTrans and inspected for fluorescence under a fluorescence microscope. Both green and red fluorescence are seen in the DNA-introduced experimental group (D-F) but not in the DNA-noninjected control group (A-C). Higher magnification of images in (D-F) reveals colocalization of both fluorescence colors in hepatocytes (G-I). In (b), the liver is dissected 7 days after EP with pT-EGFP, pT-Liv#11, and pTrans and perfusion with collagenase. Inspection for fluorescence in the dissected liver reveals bright green fluorescence in the electroporated region (A, B). When the fluorescent region is dissociated into single cells and subjected to culture in the presence of puromycin for 7 days, all of the surviving cells are found to exhibit green fluorescence (C, D), suggesting chromosomal integration of introduced transposons. (for a) and 20 μm (for b).