Fluorescein Biotin Azide is a trifunctional PEG linker containing an azide, a biotin group, and a fluorescein dye. The azide is a click chemistry handle which may be used to link with terminal alkynes or strained cyclooctynes like DBCO or BCN, while the biotin group is useful for affinity-based applications such as pull-down assays or for ligating with streptavidin proteins. Finally, the fluorescein is a near-UV/Vis spectrum dye that can be used for in vivo fluorescence assays.
