In the PromoKine Tyrosinase Inhibitor Screening Kit, Tyrosinase catalyzes the oxidation of tyrosine, producing a chromophore that can be detected at 510 nm. In the presence of a tyrosinase inhibitor (e.g. Kojic Acid), the rate of oxidation of the substrate is decreased. The kit provides a rapid, simple, sensitive, and reliable test suitable for high-throughput screening of tyrosinase inhibitors. This assay is also adaptable to a 384-well format.