FIG. 3.

Transduction by FV vectors occurs only in cells that have undergone DNA synthesis. (A and D) High-power views (magnification, ×400) of a transduced human fibroblast and a rat 208F cell, respectively, after staining for BrdU incorporation as a marker of S phase (orange-brown nucleus) and for AP expression as a marker of transduction (purple cytoplasm). (B and E) Low-power views (magnification, ×100) of panels A and B, respectively. (C and F) Same fields as those in panels B and E, respectively, under UV illumination to detect all DAPI-stained nuclei.