Fig. 1. Expression and localization of PrP^C in brain blood vessels. Transmission and immunofluorescence labeling of PrP^C and ZO-1 of brain sections from wild-type (WT) and PrP^C-deficient knockout (KO) mice. Sections of striatum were incubated with anti-PrP^C monoclonal antibodies (SAF32 plus SAF61, both at 1 µg/ml) and anti-ZO-1 polyclonal antibodies (5 µg/ml) for 16 hours at 4°C, then with Alexa Fluor 488-conjugated anti-mouse antibodies and Cy3-conjugated anti-rabbit antibodies for 45 minutes at 25°C. Images were collected with a confocal fluorescence microscope. Arrows in the left panel indicate blood vessels; insets show microvessels (chosen from a different field). Bars, 40 µm or 10 µm (inset).