Variation in DNA enrichment among deuterium labeling studies is largely explained by different background corrections

Area of Science:

• Biomedical research
• Cell dynamics
• Metabolic tracking

Background:

• Heavy water (D2O) labeling tracks cell dynamics in vivo.
• Deuterium incorporation into DNA is measured via GC-MS.
• Background correction methods for deuterium labeling vary and impact results.

Purpose of the Study:

• To compare different background correction methods for D2O labeling studies.
• To re-evaluate the amplification factor in deuterium labeling experiments.
• To propose a novel model for calculating the amplification factor.

Main Methods:

• Analysis of D2O labeling data using mechanistic binomials.
• Comparison of atom percent excess (APE) and tracer-to-tracee ratio (TTR) background correction methods.
• Re-analysis of existing deuterium labeling data.

Main Results:

• Subtracting background TTR provides a more accurate measure of deuterium enrichment than APE.
• Previous studies using APE underestimated the amplification factor by approximately 25%.
• The proposed binomial model explains variations in amplification factors due to metabolic differences.

Conclusions:

• The TTR method is superior for background correction in D2O labeling studies.
• Accurate background correction is crucial for reliable quantification of cell dynamics.
• A novel binomial model improves the understanding of deuterium incorporation into DNA.