This anti-tetramethylrhodamine rabbit IgG antibody efficiently binds and quenches ~75% of the fluorescence of tetramethylrhodamine. This antibody enables the use of the tetramethylrhodamine dye as a hapten instead of biotin. Unlike biotin, which is an endogenous ligand in mitochondria, dye-based haptens permit background-free staining of cells and tissues and a sensitive alternative to biotin-streptavidin methods.