AbFluor™ dyes are a series of highly water-soluble fluorescent dyes spanning the visible and near-infrared spectrum for Labeling biomolecules, especially proteins and nucleic acids. AbFluor™ dyes bear the core structures of different fluorescent dye core structures that cover the fluorescence spectrum from UV to NIR. Innovative modifications to the core structure makes AbFluor™ dyes superior to other commercial dyes with many innovative novel features. AbFluor™ 647 is a far-red fluorescent dye optimally excitable by the 633 nm argon laser line, which is super alternative to Cy5, Alexa Fluor 647. It yields biologically more specific antibody conjugates and less background.