Reactive fluorescent dyes compositions and methods of using same are disclosed. Coumarin nucleus or aza coumarin nucleus dyes are disclosed dyes are disclosed having thiol-reactive groups. Coumarin nucleus or aza coumarin nucleus dyes are disclosed that exhibit a fluorescence emission of at least about 575 nm. Biosensors are disclosed having a binding protein and a Coumarin nucleus or aza coumarin nucleus.
Reactive fluorescent dyes compositions and methods of using same are disclosed. Squaraine nucleus, Nile Red nucleus, benzodioxazole nucleus, coumarin nucleus or aza coumarin nucleus dyes are disclosed having thiol-reactive groups. Squaraine nucleus, Nile Red nucleus, benzodioxazole nucleus, coumarin nucleus or aza coumarin nucleus dyes are disclosed that exhibit a fluorescence emission of at least about 575 nm. Biosensors are disclosed having a binding protein and a squaraine nucleus, Nile Red nucleus, benzodioxazole nucleus, coumarin nucleus or aza coumarin nucleus.