An alternative protecting scheme for the normal CE phosphoramidites should allow UltraMILD deprotection and should not react with a wider variety of tags and labels. A set of monomers using phenoxyacetyl (Pac) protected dA and 4-isopropyl- phenoxyacetyl (iPr-Pac) protected dG, along with acetyl protected dC, met the desired criteria for UltraMILD deprotection.
Coupling: This support should be used in a manner identical to normal protected nucleoside support since it contains the DMT group. To avoid any exchange of the iPr-Pac group on the dG with acetyl, use the UltraMild Cap Mix A (40-4210-xx/ 40-4212-xx).
Deprotection: UltraMILD deprotection: 0.05M Potassium Carbonate in Methanol, 4 hours at Room Temperature OR 2 hours at Room Temperature in 30% Ammonium Hydroxide.