Depending on your specific application, Gene Link can provide Carboxy-C10-modified oligos either with the carboxyl group NHS-protected (Version 1, catalog #:26-6452) with oligo bound to CPG solid support, or as the free carboxyl (Version 2, catalog#: 26-6717).
5'-Carboxy-Modifier C10 succinimidyl ester (NHS) can be used to incorporate an active carboxyl group onto the 5'-end of an oligonucleotide or an NHS group. The carboxyl group is separated from the 5'-end nucleotide base by a 10-carbon spacer arm to minimize steric interaction between the reactive group and the oligo. The presence of the carboxyl group allows the user to 5'-end label the oligo with a variety of different affinity, reporter or protein moieties (as primary amines/thiols or maleimides), depending on the application. Examples include biotin, digoxigenin, fluorescent dyes or quenchers, and enzymes (for example, alkaline phosphatase).
Version 1 NHS protected carboxyl (catalog#: 26-6452) is supplied as oligo bound to CPG solid support and the 5' has an active NHS group. The important advantage of this NHS modification is that conjugation to the desired ligand is accomplished while the oligonucleotide is still attached to its solid support. This property enables the conjugation reaction to be carried out in an anhydrous organic solvent system, facilitating the linking of even very lipophilic moieties to oligos. In many cases, the presence of the lipophile also allows the lipophile-oligo conjugate to be efficiently purified by reverse-phase HPLC or reverse-phase cartridge.
Version 2 (catalog#: 26-6717) is supplied as completely deprotected oligo with free carboxyl group ready for conjugation to the selection of functional groups that reacts with carboxyl group.