Peptide nucleic acid molecular beacons for the detection of PCR amplicons in droplet-based microfluidic devices

The use of droplet-based microfluidics and peptidenucleic acid molecular beacons for the detection ofpolymerase chain reaction (PCR)-amplified DNA sequenceswithin nanoliter-sized droplets is described in this work. Thenanomolar–attomolar detection capabilities of the methodwere preliminarily tested by targeting two different singlestrandedDNA sequences from the genetically modifiedRoundup Ready soybean and the Olea europaea genomesand detecting the fluorescence generated by peptide nucleic acid molecular beacons with fluorescence microscopy. Furthermore,the detection of 10 nM solutions of PCR ampliconof DNA extracted from leaves of O. europaea L. encapsulatedin nanoliter-sized droplets was performed to demonstrate thatpeptide nucleic acid molecular beacons can discriminateO. europaea L. cultivar species carrying different singlenucleotidepolymorphisms