O-propargyl-puromycin (OPP CAS 1416561-90-4) is an alkyne-functionalized derivative of puromycin commonly utilized to detect and quantify newly synthesized proteins It incorporates into nascent polypeptides by acting as a translation terminator covalently attaching to their C-terminal ends Subsequent detection occurs through azide-alkyne cycloaddition under copper(I) catalysis facilitating visualization or isolation of actively produced proteins In cellular and animal models OPP labeling enables measurement of global protein synthesis rates and assessment of responses to various stimuli or stress conditions contributing significantly to proteomics and cell biology research