Like other sulforhodamine dyes, the highly water-soluble sulforhodamine B can be used as a polar tracer for cell morphology and neuronal cell-cell communication studies. Sulforhodamine B has also been shown to be a superior protein stain for quantification of cellular proteins in cultured cells. The dye is believed to bind to basic amino acids of proteins, and colorimetric measurement of protein-bound dye provides an estimate of the total protein mass as a measure of cell number. The assay is simple and reproducible, and the end-point measurement is not time-critical, a significant advantage over tetrazolium-based assays. The intensely colored, water-soluble dye is particularly useful for in vitro cell-based screening of anticancer drugs and well-suited to large scale screening of anticancer drug candidates from natural extracts or synthetic chemicals. Properties: Ex/Ex = 565/586 nm; Red solid soluble in water; Store at room temperature; C27H30N2O7S2; MW: 559; [2609-88-3]