The EZH2 (Y641F) Chemiluminescent Assay Kit is designed to measure activity of the mutant EZH2 complex (EZH2 (Y641F)/EED/SUZ12/RbAp48/ AEBP) for screening and profiling purposes. The EZH2 (Y641F) Chemiluminescent Assay Kit comes in a convenient format, with wells precoated with histone H3 peptide substrate, an antibody against methylated K27 residue of Histone H3, the secondary HRP-labeled antibody, S-adenosylmethionine, methyltransferase assay buffer, and purified EZH2 (Y641F) complex for 96 enzyme reactions. The key to the EZH2 (Y641F) Chemiluminescent Assay Kit is a highly specific antibody that recognizes methylated Histone H3K27. With this kit, only three simple steps on a microtiter plate are required for methyltransferase detection. First, S-adenosylmethionine is incubated with a sample containing assay buffer and methyltransferase enzyme for one hour. Next, primary antibody is added. Finally, the strips are treated with an HRP-labeled secondary antibody followed by addition of the HRP substrate to produce chemiluminescence that can then be measured using a chemiluminescence reader.