Abstract: Accordingly, the present invention is directed to biological compounds derivatized so as to contain at least one perfluoro-t-butyl moiety for use in fluorine-19 NMR and/or MRI studies. The perfluoro-t-butyl (PFTB) moiety, ##STR1## is an excellent reporter group for fluorine-19 NMR/MRI. It is a source of nine magnetically equivalent fluorine nuclei which generate a single intense resonance for easy detection in spectroscopy or imaging. This signal is a sharp singlet, not split by neighboring nuclei or spread over a wide frequency range and eliminates any chance of ghost images which might arise from multiple resonances. These spectral properties ensure a maximum signal-to-noise ratio (S/N) for readily detecting this moiety. The foregoing allows either reduction in the concentration of the derivatized compound, ability to use MRI instruments with lower field strengths, a reduction in imaging times, or a combination of the foregoing as a result of this moiety producing a single, sharp, intense resonance.