CF® Dye TFP Esters are amine-reactive fluorescent dyes for labeling antibodies and other proteins. TFP (tetrafluorophenyl) ester is a more stable alternative to succinimidyl ester (SE or NHS ester). • CF®850 is one of Biotium's next-generation near-infrared dyes with absorption/ emission at 852/870 nm. • CF®870 is one of Biotium's next-generation near-infrared dyes with absorption/ emission at 877/915 nm.