Click-iT® AHA Alexa Fluor® 488 Protein Synthesis HCS Assay Kit provides a rapid, convenient way to detect nascent protein synthesis. Sensitive, non-toxic and non-radioactive method for detection using fluorescence microscopy and high-content imaging. Click-iT® AHA is a methionine analog containing an azide group. Like 35S-methionine, Click-iT® AHA can be added to cultured cells and incorporated into proteins during active protein synthesis. Detection of incorporated amino acids utilizes a chemoselective ligation, or "click" reaction between an azide and an alkyne, using green fluorescent Alexa Fluor® 488 Alkynes to detect azido-modified proteins. The Click-iT® AHA Alexa Fluor® 488 Protein Synthesis HCS Assay Kit has been used in 549 and U-2 OS cells using a variety of reagents that inhibit protein synthesis (including cycloheximide, anisomycin, and puromycin) and Dose-responsiveness and minimum/maximum dose modalities were successfully tested.