Transduced MKs retain typical MK morphology and phenotype. PEG-rHuMGDF–cultured cells that were incubated with AdCNLacZ or control were harvested for simultaneous analysis of β-gal expression and GPIIb-IIIa activation. Cells were incubated with PE-GPIb antibody (or PE-IgG control) and FITC-PAC1 in the presence or absence of TRAP before fixation and in situ X-gal staining. In each set of 4 photomicrographs, the first panel shows images using light transmission microscopy, the second and third show the same field using fluorescence microscopy, and the fourth shows a computer generated overlay of the first 3 images. (A through D) Virus control, PE-IgG control, FITC-PAC1, unstimulated for light transmission, PE fluorescence, FITC fluorescence, and overlay, respectively. (E through H) AdCNLacZ, PE-GPIb, FITC-PAC1, TRAP for light transmission, PE fluorescence, FITC fluorescence, and overlay, respectively. Note that in these black and white light transmission images X-gal–stained nuclei appear as black instead of blue. The arrow indicates a successfully transduced morphologic and phenotypic MK. All photomicrographs are 400×.