Fig. 6.

Top: The corresponding ex vivo fluorescence images acquired from the Odyssey Imaging system of (a) mouse image injected with 25 μM ICG, (b) mouse image injected with 25 μM ethanolamine-2-nitroimidazole-ICG, (c) and (d) corresponding images of two mice injected with 25 and 15 μM piperazine-2-nitroimidazole-ICG, respectively, (e) through (h) corresponding IHC stains ($40\times$, brown) at low tumor hypoxic area as marked at corresponding images, (m) through (p) corresponding IHC stains ($40\times$) at higher hypoxic area, (i) through (l) corresponding IHC stains at low hypoxic area ($400\times$, brown), and (q) through (t) corresponding stains at higher hypoxic area. Scale bar is 1 mm in images. Bottom: Percentage of hypoxic area from low fluorescence intensity area (green) and higher intensity area (red) of samples (b) through (d).