Detection of Cystic Fibrosis Transmembrane Conductance Regulator DeltaF508 Gene Mutation Using a Paper-Based Nucleic Acid Hybridization Assay and a Smartphone Camer

Diagnostic technology that utilizes paper substrates and device cameras offers opportunities for development of cost effective point-of-care technologies. The translation of assays operating in aqueous solution require further development for implementation in paper substrates. This report presents and compares two methods for determination of oligonucleotides that serve as indicators of Cystic Fibrosis, differentiating wild type and mutant type sequences containing a 3-base deletion. The transduction strategy operates by selective hybridization of dye-labelled oligonucleotides (target or reporters) to capture probes immobilized on quantum dots, and hybridization results in emission of dyes via resonance energy transfer. Detection is based on hybridization of fluorophore labelled target, or hybridization of unlabelled target and labelled reporter in a sandwich assay format. Selectivity to determine mismatched sequences required control of stringency conditions using formamide as a chaotrope. It was determined that both formats can distinguish between wild type and mutant type samples on paper substrates.