Seeing Red

HeLa cell expressing CLONTECH's DsRed in mitochondria and Cyan Fluorescent Protein in the nucleus, visualized by overlaying fluorescence microscopy images

Green fluorescent protein (GFP), isolated from the jellyfish Aequorea victoria, has been a valuable tool for researchers monitoring gene expression and protein distribution in living cells. Part of the appeal of using GFP to track gene expression is that it does not require addition of substrates or cofactors for detection, but is visualized simply by applying UV or blue light radiation.¹ Over the past few years, CLONTECH of Palo Alto, Calif., has expanded on this bright idea with its Living Colors family of fluorescent proteins. Reporters expressing proteins that glow in hues of blue, cyan, and yellow have been constructed by making GFP chromophore mutations that alter emission wavelength. Recent addition of the Living Colors DsRed Red Fluorescent Protein to this family makes simultaneous detection of multiple reporter...