The 5-Methylcytosine & 5-Hydroxymethylcytosine DNA Standard Set is a set of three standards that are linear dsDNA at a length of 897 bp. All DNA standards have the same sequence (see protocol for sequence), the only difference being that each standard contains either 100% unmodified cytosines, 5-methylcytosines, or 5-hydroxymethylcytosines. Since the sequence and extent of cytosine modification is known, this DNA standard set is ideal for use in calibration of various applications intended for quantitation of cytosine modifications.