PC Amino-Modifier Phosphoramidite

The disulfide thiol modifier may be used for introducing 3’- or 5’-thiol linkages. Dithiol Serinol, produced from lipoic acid and our patented serinol backbone, allows easy connection of multiple dithiol-labelled oligos to gold surfaces. 5’-Carboxy-Modifier C10 is a unique linker designed to be added at the terminus of an oligonucleotide synthesis. It generates an activated carboxylic acid N-hydroxysuccinimide (NHS) ester suitable for immediate conjugation on the synthesis column with molecules containing a primary amine, resulting in a stable amide linkage. An alternative carboxylate protecting group is the 2-chlorotrityl group, which is simply removed using the standard deblock cycle to generate a free carboxyl group on an otherwise fully protected oligonucleotide. The 2-chlorotrityl group is also removed during oligo deprotection with ammonium hydroxide or AMA and is incompatible with RP purification techniques. PC Amino-Modifier is a photocleavable C6 amino-modifier, part of our line of photocleavable (PC) modifiers. 5’-AminoOxy-Modifier 11 is based on a tetraethylene glycol linkage for improved solubility and for reducing the potential negative impact on hybridization of the oligo. The oxime formed from the reaction of alkyloxyamines with aldehydes creates a stable covalent bond. In comparison, the imine formed by the conjugation of primary amines with aldehydes is not stable to acidic or basic conditions and requires subsequent reduction with borohydride to form stable amine conjugates. 5’-Maleimide Modifier Phosphoramidite, developed at the University of Barcelona, incorporates a maleimide cycloadduct that is stable to ammonium hydroxide at room temperature. This phosphoramidite can be incorporated into DNA and RNA with both phosphate and phosphorothioate linkages. A retro–Diels-Alder reaction deprotects the maleimide immediately prior to conjugation.