Detection of methylated DNA

摘要

The use of ion sensitive field effect transistor (ISFET) to detect methylated nucleotides in a DNA sample is described. A method of detecting methylated nucleotides in a DNA sample may include the steps of treating a sample of DNA with a reagent which discriminates between methylated and non-methylated nucleotides to provide treated DNA, amplifying the treated DNA and optionally sequencing the amplified DNA. An ISFET is used to monitor the addition of one or more dNTPs in the strand extension reactions during the amplification and/or sequencing step. Suitable apparatus is also provided.

主权项

1. An apparatus for use in a method of detecting methylated nucleotides, comprising:
(i) a first well, in which a first Ion Sensitive Field Effect Transistor (ISFET) having a floating gate arranged to monitor addition of one or more dNTPs to DNA strands during strand extension reactions when a first sample containing methylated DNA is brought into contact with the first ISFET when the first sample is loaded into the first well; (ii) a second well, in which a second ISFET having a floating gate arranged to monitor addition of one or more dNTPs to DNA strands during strand extension reactions when a second sample containing reference DNA is brought into contact with the second ISFET when the second sample is loaded into the second well; wherein the first well is separated from the second well; (iii) means for treating DNA in the first well and the second well of a microfluidic chamber with bisulfite which discriminates between methylated and non-methylated nucleotides; (iv) means for amplifying the treated DNA in the first well and the second well of a microfluidic chamber; and (v) a processor comprising a circuit, which is electrically coupled to an output of the first ISFET and an output of the second ISFET, wherein the circuit is arranged to provide an output signal of relative methylation, which output signal is derived from signals received from the first ISFET and the second ISFET.