Click-iT® homopropargylglycine (HPG) provides a fast, sensitive, non-toxic and most importantly non-radioactive alternative to the traditional technique,35S methionine for the detection of nascent protein synthesis. HPG is an amino acid analog that contains a very small modification, specifically an alkyne moiety that can be fed to cultured cells and incorporated into proteins during active protein synthesis. Detection utilizes the chemoselective ligation or “click" reaction between and azide and an alkyne where the alkyne modified protein is detected with an azide-containing dye or hapten together with either the Click-iT® Cell Reaction Buffer Kit or the Click-iT® Protein Buffer Kit. With the Click-iT® Cell Reaction Buffer Kit, cells can be analyzed by fluorescence microscopy, flow cytometry or high-content imaging and analysis. With the Click-iT® Protein Reaction Buffer Kit, achieve detection sensitivity in 1-D gels and western blots in the low femtomole range or perform LC-MS⁄MS and MALDI MS analysis.