In Vivo Fluorescence Imaging

Immediately prior to each MRI time point, fluorescence images of mice were obtained an IVIS Spectrum (PerkinElmer, Waltham, MA). Mice held under 3% inhaled isoflurane anesthesia for the duration of imaging. Mice were placed on their right or left side to image the NDG tumor or unlabeled tumor, respectively. For m-Cherry fluorescence readouts, an excitation wavelength of 580 nm and emission wavelength of 620 nm were used. Mice were allowed to recover and ambulate for several minutes before MR imaging. Image data were processed using Living Image software. ROIs were defined corresponding to each tumor and used to determine background subtracted radiant efficiency.