Cayman’s Protein Synthesis Assay Kit is a non-radioactive method for measuring protein synthesis that employs the cell-permeable, alkyne-containing, puromycin analog O-Propargyl-puromycin (OPP). Upon application to cells, the OPP probe incorporates into the C-terminus of translating polypeptide chains, thereby stopping translation. These truncated C-terminal alkyne-labeled proteins are then subsequently detected via copper-catalyzed click chemistry using 5 FAM-Azide. The reagents provided in the kit are sufficient to run 20 samples when using flow cytometry or 100 samples when using a 96-well plate format.