An ISFET based translinear sensor for DNA methylation detection

This paper presents the concept of using a novel ISFET-based readout circuit for ratiometric detection of DNA methylation, which gives a discrete answer once a certain percentage of methylation is reached. This allows the development of a tool for the early detection of multiple cancer types using a minimally invasive approach, by determining the differences between a pathogenic gene through cancer development and a normally methylated one. Analysis of such ratiometric markers will be based upon the proportion of methylated sites presented above a pre-defined, empirically set threshold value, using ISFETs in standard CMOS. The designed circuit utilizes the weak-inversion region of operation to allow analogue computation at low complexity and power coming from methylated and unmethylated DNA concentrations, by following the translinear principle of current division of biochemical signals.