Since Zamecnik and Stephenson first developed oligonucleotides as genetic-engineering tools in 1978, multiple DNA or RNA analogues have been introduced, such as peptide nucleic acid (PNA) and hexitol nucleic acid (HNA). Besides, another novel class of RNA derivatives, Locked Nucleic Acids (LNA or LocNA), was reported by the Wengel and Imanishi laboratories in 2001. Since the synthesis protocol of LocNAs is similar to that of DNA or RNA, LocNAs can be easily incorporated into kinds of qPCR detection chemistries, such as Dual-Labeled probes, Molecular Beacons and Scorpions Probes, to fine tune the properties of oligomers. Therefore, LocNA probes have been successfully served as a kind of powerful tools for biomedical research and detections.
As shown in Figure 1, compared with the conventional DNA monomer structure, there is an additional methylene bridge connecting the 2'-O and the 4'-C of the ribose ring in the LocNA monomer structure. Apparently, this bridge locks the conformation and limits the flexibility of the ribose. Consequently, the duplexes made by LocNA and other nucleic acids could be more stable.
Figure 1. Structures of (A) Locked Nucleic Acid (LocNA) and (B) conventional DNA monomers.
Besides allele discrimination, there are also many applications of LocNA probes, such as detections for SNP and pathogen, viral load quantification, gene-related analysis and Multiplexing, etc. In addition, it has been reported that LocNA probes can also be used in antisense mRNA technology.
Our company can design and synthesize various LocNA probes. The details are shown below: