Knockdown of VPS34 was achieved by transfecting U-87 MG cells with VPS34 specific validated siRNA (Silencer® select Product # s10517). Western blot analysis (Fig. a) was performed using whole cell extracts from the VPS34 knockdown cells (lane 3), non-specific scrambled siRNA transfected cells (lane 2) and untransfected cells (lane 1). The blots were probed with VPS34 Polyclonal Antibody (Product # PA1-46456, 1:1000 dilution) and Goat anti-Rabbit IgG (H+L) Superclonal™ Secondary Antibody, HRP conjugate (Product # A27036, 0.25 µg/mL, 1:4000 dilution). Densitometric analysis of this western blot is shown in histogram (Fig. b). Decrease in signal upon siRNA mediated knock down confirms that antibody is specific to VPS34.