Understanding Locked Nucleic Acid (LNA) Phosphoramidites in 60 Seconds

LNA Phosphoramidites are specialized reagents used in oligonucleotide synthesis to incorporate Locked Nucleic Acid (LNA) modifications into DNA or RNA sequences. These bicyclic nucleic acids feature a "locked" conformation, created by linking a ribonucleoside between the 2'-oxygen and 4'-carbon atoms with a methylene unit. Available in four standard types corresponding to DNA bases, LNA phosphoramidites are compatible with standard automated DNA synthesis protocols, requiring only minor modifications to synthesis cycles. Oligonucleotides containing LNA exhibit exceptionally high thermal stability and binding affinity towards complementary DNA and RNA sequences, making them valuable in various molecular biology applications such as SNP genotyping, allele-specific PCR, and as highly specific probes in hybridization assays. While LNA phosphoramidites require longer coupling and oxidation times due to increased steric hindrance, they offer great versatility, as LNA can be mixed with DNA, RNA, and other nucleic acid analogs, modifiers, and labels. Commercially available from various suppliers, LNA Phosphoramidites provide researchers with a powerful tool to enhance oligonucleotide performance, particularly in applications demanding high binding affinity and specificity.