Figure 5.

Comparison of ²H-incorporation into DNA-bound deoxyribose and protein-derived alanine in colon cancer cell lines following incubation in the presence of 5% ²H₂O over 96 h. Representative images of colon cancer cell lines (A). Excess molar enrichment in the M₁ isotopomer (EM₁) over time in DNA-derived deoxyribose (B) and protein-derived alanine (C) in human colon cancer cell lines grown under identical conditions. Inset: fractional synthesis rate constant (k), half-life (t_1/2) and goodness-of-fit (R²) from non-linear curve fitting. Three replicates were performed for each time point. Error bars represent the standard error of the mean (SEM).