Heat-transfer resistance based biosensor to detect mutation in patients with PKU

Abstract

Purpose: This study was intended to develop a label-free, simple sensing platform that can detect SNPs in the exons of the PAH gene based on heat transfer resistance (Rth). This technique was developed with short DNA strands by van Grinsven et al., 2012. The objective of this study was to extend this principle towards exon-size DNA fragments to simplify gene-screening arrays. A main focus point was to determine the maximum length of DNA that can still be employed for this Rth platform. Subjects and Methods: The immobilization efficiency of longer DNA was determined with confocal fluorescence microscopy by analysing the NCD, to which probe ssDNA of different lengths were attached and hybridized with detection probes labelled with Alexa Fluor® 488. Following this, the suitability of these long strands for Rth measurements was checked by attaching synthetic probe strands encompassing the sequence of 4 PAH gene exons: 5 (98 bp), 7 (150 bp), 9 (66 bp), and 12 (123 bp), and hybridizing them