Effect of vitamin B12-deficiency on % 5 mdC¹ for DNA extracted from coagulated blood clots² and uncoagulated EDTA-blood cell pellets³.

1Methyldeoxycytidine as a percentage of total deoxycytidine in DNA digests, measured by LC-MS/MS (see Methods). 2Post-centrifugation, blood clots were retained after serum was removed from serum blood tubes. 3Post-centrifugation, blood cell pellets were retained after plasma was removed from EDTA-blood tubes. 4Results for all assayed blood clot DNA. 5Matched data for blood clot and EDTA-blood cell pellet DNA from the same subjects. 6Subjects with plasma vitamin B12 more than 148 pmol/L. 7Subjects with plasma vitamin B12 less than 148 pmol/L. *Power analysis: >80% confidence to detect a 2% difference in means [62].