Colocalization of tPA with vWF and GH. (A) tPA versus vWF. Uninfected HUVEC were fixed, permeabilized, and stained with biotinylated sheep anti-tPA antibody followed by rhodamine-conjugated avidin and then FITC-conjugated goat anti-vWF. (B) tPA versus GH. GHrAd-infected HUVEC were fixed, permeabilized, and stained with biotinylated sheep anti-tPA and rabbit anti-GH antibodies, followed by rhodamine-conjugated avidin and then FITC-conjugated antirabbit antibody. Scanning confocal microscopy images were obtained at 0.36-μm intervals in the Z-axis using a 100× objective. Shown are representative scans from the approximate midsection of the Z-axis. The red and green images were merged to demonstrate colocalization, which appears yellow.