Dansyl amide explained

Dansyl amide is a fluorescent dye that forms in a reaction between dansyl chloride and ammonia. It is the simplest representative of the class of dansyl derivatized amines, which are widely used in biochemistry and chemistry as fluorescent labels.^[1] The dansyl amide moiety is also called a dansyl group, and it can be introduced into amino acids or other amines in a reaction with dansyl chloride.^[2] The dansyl group is highly fluorescent, and it has a very high Stokes shift. The excitation maximum (ca 350 nm) is essentially independent on the medium, whereas the emission maximum strongly depends on the solvent and varies from 520 to 550 nm.^[3]

Notes and References

1. Misra A, Tripathi S, Misra K . Fluorescent labelling of ribonucleosides at 2'-terminus; comparative fluorescence studies . Nucleic Acids Symp. Ser. . 44. 44 . 291–2 . 2000 . 10.1093/nass/44.1.291 . 12903383.
2. 10.1016/0003-2697(81)90534-0 . Tapuhi Y, Schmidt DE, Lindner W, Karger BL . Dansylation of amino acids for high-performance liquid chromatography analysis . Anal. Biochem. . 115 . 1 . 123–9 . July 1981 . 7304940.
3. Makoto Asano, Frangoise M.Winnik, Takashi Yamashita, and Kazuyuki Horief. Fluorescence Studies of Dansyl-Labeled Poly(iV-isopropylacrylamide)Gels and Polymers in Mixed Water/Methanol Solutions. Macromolecules, 1995, 28, 5861—5866.