New LNA oligo and probe
The LNA oligos (Locke Nucleic Acid) are oligos that contain a modification to the nucleic acid: in practice a methylene bridge is added that connects the oxygen to the 2 'to the 4' carbon of the pentose ring.
This bridge "blocks" the carbon which does not require protection as for the other nucleotides; LNA oligos are soluble in water or in buffer, since the modification involves only the nucleic acid skeleton and does not interfere with the nucleosides, so the solubility remains unchanged.
The advantages of LNA oligos:
- greater thermal stability
- increased hybridization specificity
- increase in Tm for short and AT-rich primers and probes AT (ΔTm / base blocked about 2-6 ° C depending on sequence composition and "neighborhood" effects)
- improved stability both in vitro and in vivo thanks to increased resistance to endo and exonuclease
- Non-toxic, efficient and effective building blocks for incorporation into antisense, m-RNA or other nucleic acid drug development candidates
LNAs are useful when:
- mismatch / SNP / allelic must be discriminated
- very early cT values
- when the background signal to signal ratio is very high
- they facilitate the design of probes for very specific targets or in which the sequence is very discriminating