Abstract: Method to perform a PCR assay that comprises the following steps: a. Obtaining a nucleic acid sample; b. Hybridizing that nucleic acid sample to one or more pair of primers where at least one primer consists of a single stranded DNA polynucleotide having a length of 60 or more nucleotides; c Subjecting said nucleic acid sample to a PCR, wherein the reaction mixture medium contains at least one of said primers; and d. Detecting the length of the amplified products. The amplified nucleic acid may contain any sequence or multiple sequences of STRs (short tandem repeats), genes or any coding region having a defined location on a genome. The preferred nucleic acid samples to be amplified are degraded or fragmented and contain one or more genetic markers.

Abstract: A method for reducing the efficiency of primer extension by polymerase enzymes when the 3? end of a primer or growing nucleic acid chain does not hybridize perfectly with the target, for increasing the selectivity of single nucleotide mutation or gene analyses, for suppressing false positive results and for enhancing the fidelity of the amplification of nucleic acid fragments by avoiding the incorporation of mispairs, the method comprising the steps of: (a) obtaining a nucleic acid sample; (b) hybridizing said nucleic acid sample to a primer; (c) subjecting said nucleic acid sample hybridized to a extension reaction by extending a primer with a polymerizing enzyme; and (d) detecting the presence of extension products; wherein the reaction extension mixture medium contains an intercalating agent such as ethidium bromide, dihydroethidium, ethidium homodimer-1, ethidium homodimer-2, acridine, propidium iodide, YOYO®-1 or TOTO®-1.