Be coupled in an iterative manner similar to standard phosphoramidites.5,6 The resulting oligonucleotideoligospermine conjugates (illustrated above and in Figure 2, Page 2) are known as “Zip Nucleic Acids” or “ZNA,7 a term that reflects
OligOnucleOtide OligOspermine cOnjugate
the presumed mode of action of the conjugates that are believed to use the oligospermine to seek out and move along (scan) oligonucleotide strands until the probe complementary sequence is located. The oligospermine then performs the function of stabilizing the formed duplex by reducing electrostatic repulsion, thereby leading to significantly increased binding affinities. Despite this increase, ZNAoligonucleotides still retain the ability to discriminate mismatches, doing so to the same extent as unmodified DNA.8 Moreover, the oligospermine can be located at the 3′ or 5′ terminus depending on the application, producing the same beneficial effects to the binding affinity. ApplIcAtIons of ZnAolIgos Since their inception, an increasing number of applications are being found for ZNAthat take advantage of their unique properties. For example, their use as primers for PCR and reverse transcription has been examined.9 ZNAoligos were found to drive PCR reactions very efficiently at higher annealing temperatures, substantially lower primer, substrate and magnesium concentrations, and faster cycling timeframes compared to DNA and LNA primer controls. The latter feature is a result of the “Zip” character of ZNA which also results
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in higher probe sensitivity presumably by increasing the local concentration of the probe in solution.472-61-7 References The primer Tm could be easily and predictably tuned simply by the addition of spermine units.102121-60-8 web Such properties make ZNAideal for multiplex PCR and PCR of AT-rich regions that are typically problematic due to the low Tm of the corresponding duplexes. Figure 3 shows the comparative PCR performance of ZNAand DNA primers on an AT-rich sequence. ZNAoligos also have notable advantages when used as primers for reverse transcription (RT).9 In this respect, it was shown that ZNAprimers improve the yield of RNA to cDNA conversion under standard conditions that led to earlier detection in RT-qPCR quantifications compared to DNA. As a result, this leads to more accurate quantification of lowabundant transcripts. Moreover, the primers in such applications were found to be more robust to variations in buffer environment compared to unmodified DNA primers. The properties of ZNAmolecules make them ideal for use as dual-labelled hydrolysis probes for qPCR. 3′-Attached oligospermine-oligonucleotide conjugates can be made shorter than their nonmodified counterparts leading to improved single-nucleotide polymorphism discrimination (Figure 4, Page 3).PMID:30969609 8 In addition, longer ZNAof a length similar to that used for non-modified probes, exhibited reduced background fluorescence through increased quenching, thus generating improved signal-to-noise ratios. Such a finding opens the way for ZNAto be used as non-hydrolysis probes. Due to the predictable increases in Tm afforded to the molecules by the attached spermine units, it is easier to design ZNAprobes compared to alternative oligonucleotide modifications such as minor groove binders (MGB) or LNA probes. Moreover, it was found that ZNAtolerated a wider range of conditions than their DNA and LNA counterparts. In a recent report by Trevisan and coworkers,10 ZNAprobes were suc.MedChemExpress (MCE) offers a wide range of high-quality research chemicals and biochemicals (novel life-science reagents, reference compounds and natural compounds) for scientific use. We have professionally experienced and friendly staff to meet your needs. We are a competent and trustworthy partner for your research and scientific projects.Related websites: https://www.medchemexpress.com
