Mab321

Surface expression of CXCR7, Flk-1, Flt-1, vWF, VE-cadherin, and CD31 was evaluated by flow cytometric analysis. Cells were harvested with PBS containing 5 mM EDTA and immediately neutralized in FACS buffer (α-MEM containing 1% BSA and 0.025% NaN₃). After extensive washing with FACS buffer, cells (10⁵ cells) were incubated with 1 µg/ml of the primary antibodies, including CXCR7 (MAB42273, R&D Systems, 1:100 dilution), Flk-1 (Avas12a1, Novus, 1:100 dilution), Flt-1 (MAB321, R&D System, 1:100 dilution), vWF (ab8822, Abcam, 1:100 dilution), VE-cadherin (FAB9381P, R&D System, 1:100 dilution), and CD31 (FAB806G, R&D Systems, 1:100 dilution) by shaking for 1 h at 4 °C. After extensive washing with FACS buffer, cells were incubated with DyLight 649 AffiniPure goat anti-rabbit IgG or DyLight 488 AffiniPure goat anti-mouse IgG (115-495-209 or 111-545-144, Jackson Immunoresearch, 1:100 dilutions) by shaking for 1 h at 4 °C. Cells were then washed with FACS buffer five to six times, and fixed in PBS containing 1% paraformaldehyde. Expression levels were measured on a FACScalibur instrument and FACSDiva 6.0 software (BD Bioscience).