Biotin Azide Plus is a biotin probe that enables the possibility for copper-catalyzed Azide-Alkyne Chemistry (CuAAC) to biotin label alkyne or DBCO modified targets. The Azide Plus is a chemical structure that works as a strong copper-chelating system allowing the formation of a strong and active copper complex that makes Biotin Azide Plus the reactant and the catalyst in the CuAAC reaction. Therefore the reaction can be performed under diluted conditions. Once the biotin is attached to a biomolecule fluorescence microscopy detection can be carried out using the well-known signal enhancement strategy of incubation with a fluorescent streptavidin-conjugate.