Compounds and methods are disclosed that are useful for noninvasive imaging in the near-infrared spectral range. The cyanine compounds of Formula (I) are presented: (I). wherein Q is a portion of a polymethine bridge selected from the group consisting of: (a) and (b). Also included are bioconjugates of the compounds of Formula (I), methods of labeling biomolecules with the compounds, and methods of imaging.
