Fig 2. Optical measures of SO₂ are significantly lower in tumors compared with normal tissue.

A. Representative reflectance spectra (open circles) from normal tissue (blue), 4T1 (red) and 4T07 (green) murine mammary tumors, and MC model fits (solid line). These spectra were measured prior to 2-NBDG injection B. Extracted absorption spectra for the reflectance spectra shown in 2A illustrate higher absorption in the 4T1 tumor compared with the normal and 4T07 tumor. C. Baseline oxygenation levels are significantly lower in 4T1 and 4T07 tumors compared with normal tissue. D. The injection of 2-NBDG causes a statistically insignificant increase in SO₂ in normal tissue and 4T1 tumors, and no change in the control and 4T07 groups E. Oxygen consumption rates (OCR) of 4T1 and 4T07 cells are statistically similar. Measurements were made using a Seahorse Glycolysis stress test. Data represent n = 12 cell samples from 3 distinct assays. Error bars represent standard error of the mean.