MSprotected RNA phosphoramidites it was 3 minutes. However, we were concerned that the increased acidity of BTT (pKa 4.08 vs ETT pKa 4.28 vs 1H-tetrazole pKa 4.89)3 could potentially detritylate the monomer during the coupling step leading to a dimer addition. If this process were significant, the full-length oligo would be contaminated with n+1 insertion mutations. However, by examining oligonucleotides by ion-exchange HPLC, we find that n+1 peaks are no more significant using BTT with lower coupling times than ETT with a 6 minute coupling or 1H-tetrazole with a 12 minute coupling.
We are happy to announce the availability
of polystyrene columns fully compatible with the Applied Biosystems 3900 synthesizer. Initially, we are offering the regular 4 nucleoside supports, Bz-dA, BzdC, dmf-dG and dT. In the near future, we will be adding several of our most popular supports, including RNA supports, for this platform. We are also adding 96 well plates containing both of our CPG-based universal ORDERING INFORMATION
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supports, as well as dT. Universal Support 1000 is suitable for preparing unmodified oligonucleotides. Any regular or modified oligonucleotide, including RNA, can be prepared using Universal Support II. The dT support should find favor among researchers preparing siRNA oligos. These plates are offered initially filled at the 40 nmole level. The support is held tightly in the wells with porous frits, which help to disperse the liquid flow more evenly through the support bed, while avoiding the splashing of support that is virtually inevitable in loosely filled wells.
Nucleic Acid (LNA) was first described by Wengel and co-workers in 19981 as a novel class of conformationally restricted oligonucleotide analogues. LNA is a bicyclic nucleic acid where a ribonucleoside is linked between the 2’oxygen and the 4′-carbon atoms with a methylene unit. The structures are detailed in Figure 1. Under licence from Exiqon A/S (Denmark), and in association with Link Technologies Ltd (Scotland), we are now able to offer the four standard LNA phosphoramidites. Oligonucleotides containing LNA exhibit unprecedented thermal stabilities towards complementary DNA and RNA2, which allows excellent mismatch discrimination. In fact the high binding affinity of LNA oligos allows for the use of short probes in, for example, SNP genotyping3, allele specific PCR and mRNA sample preparation. In fact, LNA is recommended for use in any hybridization assay that requires high specificity and/or reproducibility, e.265129-71-3 Formula g.1350653-20-1 Molecular Weight , dual labelled probes, in situ hybridization probes, molecular beacons and PCR primers.PMID:30335310 Furthermore, LNA offers the possibility to adjust Tm values of primers and probes in multiplex assays. As a result of these significant characteristics, the use of LNA-modified oligos in antisense drug development is now coming under investigation4, and recently the therapeutic potential of LNA has been reviewed.5 In general, LNA oligonucleotides can be synthesized by standard phosphoramidite chemistry using automated DNA synthesizers. The phosphoramidites can be dissolved in anhydrous acetonitrile to standard concentrations, except for the 5Me-C variant which requires the use of a 25% THF/acetonitrile solution. They are more sterically hindered compared to standard DNA phosphoramidites and therefore require a longer coupling time. 180 seconds and 250 seconds coupling times are recommended for ABI and Expedite synthesizers, respectively. The oxidation of the phosphite.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