Detection and quantification of methylation in DNA using solid-state nanopores

Sci Rep. 2013:3:1389. doi: 10.1038/srep01389.

Abstract

Epigenetic modifications in eukaryotic genomes occur primarily in the form of 5-methylcytosine (5 mC). These modifications are heavily involved in transcriptional repression, gene regulation, development and the progression of diseases including cancer. We report a new single-molecule assay for the detection of DNA methylation using solid-state nanopores. Methylation is detected by selectively labeling methylation sites with MBD1 (MBD-1x) proteins, the complex inducing a 3 fold increase in ionic blockage current relative to unmethylated DNA. Furthermore, the discrimination of methylated and unmethylated DNA is demonstrated in the presence of only a single bound protein, thereby giving a resolution of a single methylated CpG dinucleotide. The extent of methylation of a target molecule could also be coarsely quantified using this novel approach. This nanopore-based methylation sensitive assay circumvents the need for bisulfite conversion, fluorescent labeling, and PCR and could therefore prove very useful in studying the role of epigenetics in human disease.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • 5' Untranslated Regions
  • CpG Islands
  • DNA / analysis*
  • DNA Methylation
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / metabolism
  • Fluorescent Dyes / chemistry
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Humans
  • Nanopores*
  • Polymerase Chain Reaction*
  • Transcription Factors / genetics
  • Transcription Factors / metabolism

Substances

  • 5' Untranslated Regions
  • DNA-Binding Proteins
  • Distal-less homeobox proteins
  • Fluorescent Dyes
  • Homeodomain Proteins
  • MBD1 protein, human
  • Transcription Factors
  • DNA