Probing the metabolic water contribution to intracellular water using oxygen isotope ratios of PO4
Hui Li, Chan Yu, Fei Wang, Sae Jung Chang, Jun Yao, and Ruth E. Blake
PNAS
http://www.pnas.org/content/early/2016/05/10/1521038113.abstract.html?etoc
DNAのPO4-のd18Oが!