Methylsorb Technology for Detecting DNA Methylation Using Gold-DNA Affinity Interaction
A brief description: This is the surface Plasmon Resonance version of the eMthylsorb technology.
The video illustrates the basic principle of the Methylsorb approach. Briefly, DNA samples extracted from cell lines were treated with bisulphite to convert unmethylated cytosines into uracils while methylated cytosines remained unchanged. These samples were then converted to ss-DNA amplicons by an asymmetric PCR step, where methylated cytosines were copied into guanines, and uracils into adenines. The resulting ss-DNA amplicons were directly adsorbed onto a gold chip. To quantify adsorbed DNA sequences on gold chip, we used a surface Plasmon resonance (SPR) biosensing approach that detects changes in refractive index over time (i.e., changes in the SPR spectral shift) at the sensing surface, which is directly proportional to the relative mass increase associated with target adsorption, thus enabling the real-time and label-free monitoring of targets.
Impact / Significance: This sensing concept gave a completely new dimension to the field, and attracted massive interest to the biosensing community as it can overcome all major technological drawbacks in current biosensing approaches. It uses direct adsorption of target biomarkers on a bare gold chip/surface rather than the conventional approach of using recognition and transduction layers in hybridisation or immunoassays based biosensors. This is a substantial invention because it substantially simplifies the method by avoiding the complicated chemistries underlying each step of the sensor fabrication thereby significantly reduce the analysis time and assay cost.
Main Contributors: Muhammad J A Shiddiky and Laura G Carrascosa et al (2014)