DMT-locMeC(bz) Phosphoramidite

DMT-locMeC(bz) Phosphoramidite belongs to the group of LNA phosphoramidite. It is known as DMT-5-Me-locCytidine(N4-Benzoyl)- ß-Cyanoethylphosphoramidite. The synthesis cycle for Locked Nucleic Acid (LNA) oligonucleotides consists of the same series of reactions as the cycle that is employed for DNA monomers. However, the rate of coupling for LNA monomers is slower compared to that of DNA monomers (a coupling time of 8 minutes is recommended for LNA monomers compared to 90 seconds for DNA monomers). With the exception of the LNA monomers, LNA synthesis is accomplished with the same reagents as DNA synthesis.

Key Features of LNA Phosphoramidites:

• LNA oligonucleotides are prepared by phosphoramidite chemistry
• Standard DNA synthesizer platforms can be employed. No change is required in the reagents commonly used for DNA synthesis.
• To further enhance the hybridization characteristics of LNA, 5-methyl-cytidine is employed instead of cytidine.
• LNA monomers are as soluble in acetonitrile as their DNA counterparts (except for the 5-methyl-cytidine derivative, which requires the application of 10-20%, dichloromethane as a co-solvent)
• Mixmer oligonucleotides containing LNA, DNA and/or RNA monomers can be assembled easily
• LNA oligonucleotides with predefined melting temperatures (Tm) can be designed and prepared.

LNA phosphoramidites from Merck are diluted with dryacetonitrile, except for locMeC(bz)-phosphoramidite.This phosphoramidite requires the application of a cosolventto prevent crystallization from the solution onthe synthesizer. Dichloromethane or tetrahydrofuran(THF) can be applied as co-solvents with acetonitrile tocompletely dissolve locMeC(bz)-phosphoramidite.