Tryptase

Tryptase is an enzyme that is released, along with histamine and other chemicals, from mast cells when they are activated as part of a normal immune response as well as in allergic (hypersensitivity) responses. Serum tryptase is one of tests used to aid in the diagnosis of mast cell activation syndrome.

enzyme a substance produced by a living organism which acts as a catalyst to bring about a specific biochemical reaction.

serum The clear yellowish fluid that remains from blood plasma after clotting factors have been removed by clot formation. (Blood plasma is simply blood that has had its blood cells removed.)