Fig. 4

Quantification of MCHB in 4T1 tumors by imaging and LC/MS/MS. a The upper left encircled figure focuses on changes within the first two hours. Representative tumor images (above the curves) at the indicated time points illustrate the change in MCHB fluorescence, which was used to calculate MCHB concentration using a standard curve. (Fluorescence in the 12 and 24 h images is not evident to the naked eye but is recorded by the camera; see text for further details. At 24 h, the concentration of MCHB is extremely low, which accounts for the high variance at this time point; at other time points, the variance is markedly lower). b Correlation analysis of the two measurements: Pearson’s r = 0.99, p < 0.0001