ULTRA-SENSITIVE METHOD FOR GASTRIC CANCER BIOMARKER DETECTION

摘要

The invention relates to an ultra-sensitive method for the detection of the gastric cancer biomarker, the reprimo gene (RPRM) methylated in a DNA sample, said method comprising: treating the DNA sample with sodium bisulphite; supplying a metal nanoparticle of between 40 and 80 nm, the surface of which includes an oligonucleotide that recognises methylated RPRM and is selected from SEQ ID Nº1 and SEQ ID Nº2 and, optionally, a Raman or fluorescence marker; supplying a second metal nanoparticle of between 8 and 20 nm or a quantum dot of between 2 and 10 nm, the surface of which includes an oligonucleotide that recognises methylated RPRM and is selected from SEQ ID Nº1 and SEQ ID Nº2, different from that contained in the first nanoparticle, and, optionally, a Raman or fluorescence marker; allowing the hybridization of the sample and both nanoparticles, and centrifuging and detecting the presence of hybrid complexes of nanoparticles and DNA in the resuspended sediment. The detection can be performed by molecular absorption and, if necessary, optionally by fluorescence spectroscopy or Raman spectroscopy.