A 1:1 mixture (v/v) of aqueous Ammonium hydroxide and aqueous MethylAmine. If carried out separately, it is accomplished in 5 minutes at room temperature. UltraFAST deprotection allows 5-10 minute deprotection of oligonucleotides using AMA. It is important to note that the UltraFAST system requires acetyl (Ac) protected dC to avoid base modification at the C base if Bz-dC is used. The three other monomers remain unchanged and the system works equally well with iBu-, Ac-, or dmf-dG, the last being our preferred dG phosphoramidite. The deprotection step is carried out at 65 for 5 minutes. Deprotection can also be carried out at lower temperatures as shown in Table 2. In all cases, no base modification has been observed. Figure 1 illustrates the differences in RP HPLC between partially and fully deprotected oligos, DMT-off and DMT-on.
Note: UltraFAST system requires acetyl (Ac) protected dC to avoid base modification at the C base. UltraMILD Deprotection Cleavage is not carried out separately when using UltraMILD techniques. Since many of our nucleosides and dye products are not stable to deprotection with ammonium hydroxide or AMA, the procedure to deprotect the labelled oligonucleotide must be changed. We often recommend using the UltraMILD monomers (Pac-dA, Ac-dC and iPr- Pac-dG) and deprotection with potassium carbonate in methanol. In this way, some of these very sensitive oligonucleotides can be conveniently isolated. If capping is carried out using Cap A containing phenoxyacetic anhydride, it is possible to deprotect UltraMILD oligonucleotides
in 4 hours at RT with 0.05M potassium carbonate in methanol or 2 hours at RT with ammonium hydroxide. Alternatively, using the regular Cap A containing acetic anhydride, it is necessary to deprotect overnight at room temperature to remove any Ac-dG formed during the capping step. For TAMRA containing oligonucleotides, an alternative deprotection3 may be carried out using t-butylamine/methanol/water (1:1:2) overnight at 55. Another option that we have found to be excellent uses t-butylamine/water (1:3) for 6 hours at 60. In this case, the regular protecting groups on the monomers may be used. An even milder approach has been described as “UltraUltraMild”.4 In this technique, Q-supports5 are combined with UltraMild monomers to allow extremely gentle deprotection.75747-14-7 Formula After completion of the synthesis, the solid support is dried and treated overnight at 55 with a solution containing 10% (v/v) diisopropylamine (iPr2NH) in 0.474-62-4 manufacturer 25 M mercaptoethanol in MeOH.PMID:28613713
suMMary Successful oligonucleotide cleavage and deprotection require consideration of the deprotection conditions for each product and some products may require pretreatment or special deprotection conditions. Each synthesis should be reviewed to ensure the products have compatible deprotection conditions. Special deprotection requirements can be found on our Analytical Reports, Certificates of Analysis, Technical Bulletins, and Website: http://glenresearch. References:
(1) S.L. Beaucage and R.P. Iyer, Tetrahedron, 1992, 48, 2223-2311. (2) M.P. Reddy, N.B. Hanna, and F. Farooqui, Nucleos Nucleot, 1997, 16, 1589-1598. (3) B. Mullah and A. Andrus, Tetrahedron Lett, 1997, 38, 5751-5754. (4) L.C.J. Gillet, J. Alzeer, and O.D. Scharer, Nucleic Acid Res, 2005, 33, 1961-1969. (5) R.T. Pon, and S.Y. Yu, Nucleic Acids Res, 1997, 25, 3629-3635.
9
NEw UNiVERsaL sUppORT – gLEN UNysUppORT
In 1997, Glen Research introduced our first Universal Support, popularly known as.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
