Plot of % 5-methyldeoxycytidine versus [³H]methyl-acceptance capacity of DNA extracted from coagulated blood clots.

<p>DNA samples were from (•) vitamin B12-deficient (plasma vitamin B12<148 pmol/L) or (□) vitamin B12-replete subjects (plasma vitamin B12>148 pmol/L). % 5-methyldeoxycytidine: 5-methyldeoxycytidine as a percentage of total deoxycytidine in DNA digests as measured by LC-MS/MS (see Methods). [3 H]Methyl-acceptance: [3 H] (cpm) from [3 H-methyl]SAM incorporated into 250 ng of DNA in the presence of Sssi DNA methyltransferase.