Preparation of an IMI dye (imidazole functional group) containing a 4-( N, N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole fluorophore for labeling of phosphomonoesters

• Published in: Journal of Chromatography A 1999-01, Vol.831 (2), p.325-330
• Main Authors: Lan, Zhang-Hua, Qian, Xiaohua, Giese, Roger W
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Chemistry; Chromatographic methods and physical methods associated with chromatography; Dyes; Electrophoresis; Exact sciences and technology; Fluorescent Dyes - chemistry; Fluorescent Dyes - radiation effects; Histamine - chemistry; Imidazoles - chemistry; Nucleotides; Nucleotides - chemistry; Other chromatographic methods; Oxadiazoles - chemistry; Oxadiazoles - isolation & purification; Ultraviolet Rays
• ISSN: 0021-9673
• DOI: 10.1016/S0021-9673(98)00953-4

We are studying dye–imidazole conjugates (“IMI dyes”) as reagents for labeling phosphomonoesters such as nucleotides. Previously we have employed a BODIPY dye in our IMI reagents, and analyzed the labeled products by capillary electrophoresis with laser-induced fluorescence detection (CE–LIF) involving an argon ion laser. (The BODIPY fluorophore is a 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene). Here we broaden the technology by preparing a DBD–IMI dye [DBD=4-( N, N-dimethylaminosulfonyl)-2,1,3-benzoxadiazole], and using a helium–cadmium laser. While DBD–IMI (IMI3) is about 50× more stable photolytically than a BODIPY–IMI dye (IMI2, a conjugate of a BODIPY dye with histamine, was tested), the detection limit for IMI2 (5·10 −11 M; S/ N=5, CE–LIF with an argon ion laser) is tenfold better than that for IMI3 (5·10 −10 M, S/ N=5, helium–cadmium laser). IMI3 conjugates of the four major DNA nucleotides were prepared and detected by CE–LIF.