In the AHCY Inhibitor Screening kit the homocysteine generated from the breakdown of SAH is measured using a Thiol Detecting Reagent resulting in enhanced fluorescence which is measured at Ex/Em = 392/482 nm. The AHCY reaction is reversible and hence Adenosine Deaminase is included in the reaction to ensure that the reaction proceeds towards hydrolysis of SAH. In the presence of AHCY inhibitor, there is a decrease in fluorescence of the Thiol Detecting Reagent.