Recombinant Ten-Eleven Translocase is a recombinantly expressed dioxygenase that depends on Fe(II) and α-ketoglutarate. It catalyzes the conversion of 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC), followed by further oxidation to 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC). Subsequently, 5caC is converted into uracil (U) through chemical or enzymatic processes, and during PCR, uracil (U) is transformed into thymine (T), allowing for single-base resolution and highly accurate identification of DNA methylation sites.