5-Methylcytosine is a methylated form of the DNA base cytosine that may be involved in the regulation of gene transcription. When cytosine is methylated, the DNA maintains the same sequence, but the expression of methylated genes can be altered (the study of this is part of the field of epigenetics). 5-Methylcytosine is incorporated in the nucleoside 5-methylcytidine.
M 7047 (OTTO) 5-Methylcytosine, 97% Cas 554-01-8 - used as a marker to protect DNA from being cut by native methylation-sensitive restriction enzymes. It is also employed in the production of 4-amino-5-hydroxy-5-methyl-2-oxo-2,5-dihydro-imidazole-1-carbaldehyde.