Quantifying Melanogenic Protein Expression

Western blots were done based on previous descriptions [40 (link)–42 (link)]. Cell lysates were separated by 10% SDS-PAGE and transferred onto PVDF membranes. The membranes were incubated with antibodies: rabbit anti-TRP1 (1 : 1000, Santa Cruz, City of Santa Cruz, CA, USA), goat anti-TRP2 (1 : 1000, Santa Cruz, City of Santa Cruz, CA, USA), rabbit anti-tyrosinase (1 : 1000, Bioworld, St. Louis Park, MN, USA), and rabbit anti-β-catenin (1 : 1000, Abcam, Cambridge, USA) at 4°C overnight. Blots were then incubated with HRP-conjugated secondary antibody (Invitrogen, Carlsbad, CA, USA) for 1 hour. Bands were visualized on the membranes using an ECL western blotting detection system.