Zip nucleic acid: a new reliable method to increase the melting temperature of real-time PCR probes

TaqMan genotyping with real-time PCR is a reliable method for single nucleotide polymorphism detection, which is done by probes. These oligonucleotides should be short enough to avoid mismatch hybridization, as well as having 5-10°C higher melting temperature than the primers of real-time PCR reaction. One approach for these qualities is to conjugate the probe with minor groove binder (MGB). Having no access to MGB probes, we searched for an alternative. In the current study, we used Zip Nucleic Acids (ZNA) as probes to increase its stability and melting temperature. Our aim was to genotype the -265 T/C changes of Apolipoprotein A-2 gene. We set up the real-time PCR reaction with ZNA probes, and by repeating the reactions, we confirmed the reliability of this new approach. It is now recommended to use ZNA probes, as an alternative to MGB probes, to increase the probe Tm value and its binding to target DNA.