Figure 2: Primary Breast Tumor. (a) – (d) Representative In vivo spectral reflectance images of the primary breast tumor 10 days after injection. On day 10, the rats were anesthetized and 10% fluorescein and/or 1% lymphazurin was injected right under the breast nipple. After 15 minutes of dye equilibration, tumors were excited with light from the Polychrome light source (450nm- 694nm in consecutive bandwidths of 20nm) and multispectral AOTF images were obtained for each excitation band (460nm-750nm range; ??= 20nm). For every excitation, the first image in the emission window constituted the reflectance image while the rest of the images in the series constituted the fluorescence images. Reflectance images at longer wavelengths (> 560 nm) clearly show tumor vasculature details below the shaved skin of the animal. (e) Graphical display of reflectance spectra in normal (left) and tumor (right) breasts from an animal after 10- days of tumor growth. The reflectance spectral signatures for 480, 520 and 580 nm excitation are significantly different between the tumor and normal breasts thereby indicating possibilities for quantitative imaging of tumor-specific signatures in tumor xenografts without surgical incision. The figure also shows the spectral reflectance profiles for blood from the same animal. (f) fluorescence image of tumor vasculature after fluorescein injection in the tumor breast (Scale bar = 1cm) and (g) auto fluorescence spectra from tumor and non-tumor breasts (h) representative immunofluorescence image obtained from a section of the breast tumor tissue showing upregulation of the glucose transporters (GLUT-1) that is a measure of tumor aggressiveness in vivo as well as (i) the metastastic potency of these tumor cells (indicated by white arrows) as shown by Akt- Alexa488 immunofluorescence labeling of the blood vessel where tumor cells are found amidst anucleated red blood cells. Scale bars = 20µm.