Oligo Synthesis : CEPs

Stability in Solution: 2-3 days

Our repertoire of NHS ester derivatives has been expanded toinclude the NHS-Carboxy-dT-CE Phosphoramidite. By making a dT analog of theCarboxy-Modifier C10, it is possible to label one or multiple sites within anoligonucleotide. This opens up the possibility to label any number of differentdyes or molecules within an oligonucleotide when the phosphoramidite isunavailable. Doing so is straightforward and may be done manually off thesynthesizer or even in a fully-automated manner on the DNA synthesizer.

We have never found conditions which allow the TFA group to be removed froman amino-modifier while the oligonucleotide remains attached to the support. Weare able to solve this problem by using a 9-fluorenylmethoxycarbonyl (Fmoc)protecting group. The Fmoc group is removed using a two step procedure, thefirst to remove the cyanoethyl protection groups and flush the formedacrylonitrile from the synthesis column using 1% diisopropylamine inacetonitrile, and the second to remove the Fmoc group using 10% piperidine inDMF. The amino group so formed on the column can be reacted with a variety ofactivated esters. We offer Fmoc-Amino-Modifier C6 dT Phosphoramidite as anucleosidic option and Amino-Modifier Serinol Phosphoramidite as anon-nucleosidic alternative. We also offer S-Bz-Thiol-Modifier C6-dT to join theranks of thiol-modifiers for oligonucleotide synthesis. Thiol-Modifier C6-dT canbe added as usual at the desired locations within a sequence.