 FRONCAT is a novel method for profiling the nascent cellular protome and capturing early proteomic changes in response to external stimuli. It uses a bio-orthogonal thronine analogue called a final serine, S, which allows for the selective visualization and enrichment of newly synthesized proteins in complete growth media within minutes. This method can be used to study the dynamic behavior of proteins in response to external stimuli in both bacterial and mammalian cells, as well as in drosophila models. Furthermore, it can be used to measure relative protein synthesis rates in specific cell types in vivo. This article was authored by Bob J. Ignacio, Jelma Dijkstra, Natalia Mora, and others.