LRB - SC [Lissamine™ rhodamine B sulfonyl chloride]
LissamineTM rhodamine B (LRB) sulfonyl chloride (SC) is a mixture of isomeric sulfonyl chlorides. Its fluorescence emission spectrum lies between those of tetramethylrhodamines and X-rhodamines, and it can be well excited by 568 nm line of the Ar-Kr mixed gas laser that is used in many confocal laser-scanning microscopes. Like FITC reagents, LRB-SC is relatively inexpensive. However, it is quite labile in basic solutions, making it somewhat difficult to achieve reproducible conjugations.
Smith SN and Steer RP (2001). The photophysics of Lissamine rhodamine–B sulfonyl chloride in aqueous solution: implications for fluorescent protein–dye conjugates. J Photochem Photobiol, A 139, 151; Neves C, et al. (2000). Novel method for covalent fluorescent labeling of plasmid DNA that maintains structural integrity of the plasmid. Bioconjug Chem 11, 51-5.