Tyrosinase is a copper-binding enzyme that is expressed across a vast range of species ranging from bacteria and fungi to mammals. It is involved in two sequential reactions of the melanin synthesis pathway. The first reaction is the hydroxylation of a monophenol, and the second reaction is the conversion of an ortho-diphenol to a quinone. Quinone subsequently undergoes a series of reactions, including polymerization, to form melanin. Tyrosinase is of great interest to the agriculture industry since it causes browning of fruits, vegetables and mushrooms, as well as to the cosmetic industry as tyrosinase causes skin darkening. Development and screening of tyrosinase inhibitors, therefore, is very useful for conditions such as hyperpigmentation and melasma. Tyrosinase activity is significantly increased in melanoma. Therefore, the detection of tyrosinase activity could be promising as a specific diagnostic test for melanoma and may be useful in monitoring patient response to melanoma treatments.

The Tyrosinase Assay Kit is a simple, one-step and reliable assay for monitoring tyrosinase activity with high sensitivity. The assay uses a colorless substrate solution that significantly increases its absorption at 510 nm upon reaction with tyrosinase. The increases in absorption at 510 nm is proportionate to the tyrosinase activity.