Western blot analysis of BMP4 in Lane 1: recombinant human BMP4 protein using 1 ng per well. Electrophoresis was performed on 5-20% SDS-PAGE gel at 70V (Stacking gel) / 90V (Resolving gel) for 2-3 hours and protein was transferred to a nitrocellulose membrane at 150mA for 50-90 minutes. Sample was blocked with 5% Non-fat Milk/TBS for 1.5 hours at room temperature, incubated with BMP4 polyclonal antibody (Product # PA5-78875) at a dilution of 0.5 µg/mL (overnight at 4°C), followed by goat anti-rabbit IgG-HRP secondary antibody at a dilution of 1:10,000. Signal development was performed using a chemiluminescence (ECL) kit.