A label-free supersandwich electrogenerated chemiluminescence method for the detection of DNA methylation and assay of the methyltransferase activityElectronic supplementary information (ESI) available. See DOI: 10.1039/c3cc00203a

A method based on electrogenerated chemiluminescence (ECL) for detection of DNA methylation and assay of the methyltransferase activity is developed, and it is demonstrated that the label-free ECL method is capable of detecting methyltransferase with a detection limit of 3 × 10 −6 U mL −1 , using a supersandwich amplification technique. A label-free supersandwich electrogenerated chemiluminescence method for the detection of DNA methylation and assay of the methyltransferase activity is developed.