Lumitein is a luminescent dye designed for detecting proteins in SDS polyacrylamide (SDS-PAGE) gels. It can also be used to detect proteins in native PAGE gels after an additional SDS incubation step. The stain combines excellent sensitivity, exceptional user-friendliness and compatibility with common instruments and downstream analysis. It is as sensitive as the best silver stain by detecting 1 ng or less protein (Figure 1). Unlike silver stain, however, Lumitein has a linear detection range of at least 3 orders of magnitude. It is among the simplest protein gel stain by staining protein in gels in 90 minutes or less time without a separate fixation step. Lumitein has an excitation spectrum that makes detection possible with either a simple UV box or a high-end laser scanner. Moreover, protein gel staining with Lumitein is compatible with downstream protein analyses such as mass spectrometry and Edman-based sequencing (Figure 2).