Click-iT® AHA (L-azidohomoalaine) provides a fast, sensitive, non-toxic and most importantly non-radioactive alternative to the traditional radioactive technique, 35S-methionine for the detection of nascent protein. AHA is an amino acid analog that contains a very small modification, specifically an azido 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 an azide and an alkyne where the azido modified protein is detected with one of the Click-iT® Protein Analysis Detection Kits containing either TAMRA, Dapoxyl®, or biotin alkyne. Detection sensitivity with these reagents in 1-D gels and Western blots is in the low femtomole range and compatible with downstream LC-MS⁄MS and MALDI MS analysis or Multiplexed Proteomics® reagents for differential analyses of newly synthesized proteins together with total glycoproteins, total phosphoproteins or total protein.