Strain promoted alkyne azide cycloaddition (SPAAC) between strained cycloalkynes and azides is a useful bioconjugation method that eliminates the need for copper catalyst necessary for classical CuAAC click chemistry.nnCyanine5.5 DBCO is a cyclooctyne product containing Cyanine5.5 fluorescent dye. This fluorophore is used in bioimaging, biodistribution studies, and microscopy.nnCyanine5.5 DBCO can be used to conjugate the fluorophore with various azides.