PDGFRαβ⁺ stromal cells are localized to perivascular and intersinusoidal regions in vivo. Whole-mount staining of BM plugs. Vascular endothelial cells were identified with VE-Cadherin–Alexa 488 and MECA32–Alexa 488 antibodies (A), and stromal cells were identified with PDGFRα/β antibodies and revealed with donkey anti–rat Cy3 (C). Nuclei were counterstained with DRAQ5. Z-stack merged image (B) and single-step merged image identifying perivascular (white asterisk) and intersinusoidal (white arrow) localization. Images were collected using a 63× oil immersion objective on zoom factor of 3 with a Leica TCS SP5 confocal microscope and processed with the Leica LAS AF lite Version 2.6.7266 software. Z-stacked images were collected in 0.2-μm slices at depths of 15 to 25 μm with a pinhole of 1.