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Reactive functional groups, such as primary amine, thiol, and carboxylate, are incorporated into oligos to enable post-synthesis conjugation with various affinity, reporter, and protein labels, as well as solid surfaces such as glass slides and gold microspheres.

Using reactive functional groups is useful for incorporating modifications that are unavailable as phosphoramidites or unstable during oligonucleotide synthesis and deprotection.

For most of the modifications, we offer phosphoramidites and reagents for incorporation to your oligo at the 3’-end, 5’-end, and internally. The reagents are available with various linker types (TEG, carbon) and protective agents (e.g., Fmoc, MMT).

​​​​​​​Acrydite modifiers

Acrydite-modified oligos covalently react with thiol-modified surfaces or can be used in polyacrylamide gels during polymerization.

Aldehyde modifiers

The aldehyde function is often used to conjugate biopolymers to other molecules via reductive amination or adduct formation with hydroxylamines, hydrazines, and semicarbazides. You can also use aldehydes to immobilize oligos onto solid surfaces.

Amino modifiers

We offer a wide range of phosphoramidites, CPG, and other reagents for incorporating amino functionalities at the 5’- and 3’-ends of an oligo or internally. You can choose the type of linker (e.g., carbon, TEG), linker length (C3 to C12), and protection group (e.g., TFA, MMT, Fmoc) that best suit your applications.

Carboxylate modifiers

Carboxylate modifiers can be used to introduce a carboxylic acid function at the 5’-end of an oligonucleotide that is available for conjugation to amines whilst still on the solid support. This strategy avoids the problems of low yields, long reaction times and the need for excess reactants often encountered by other post-cleavage solution methods. Internal carboxylate function can also be achieved.

Click reagents

We offer a wide range of Click Chemistry reagents which can be used as reliable labelling methods. Our Click-mates™ collection includes alkynes for the classic Cu(I)-catalyzed alkyne-azide cycloaddition (CuAAC) “click reaction”, as well as the streamlined copper-free click modifications. The Click-easy™ alkynes can help you to simplify bioconjugation work by employing cyclo-alkynes for efficient uncatalyzed click ligation.

Glyceryl modifiers

We offer glyceryl CPG to incorporate a glyceryl functionality at the 3' end of an oligo which is readily oxidized to an aldehyde or further oxidized to the corresponding carboxylic acid. Either the aldehyde or the carboxylate may be used for conjugation to amino-functionalised biomolecules. This is an effective strategy for 3' post-synthetic modification with amines, as 3'-functionalised carboxylate and aldehyde solid supports are not commonly available.


We offer hydrazide phosphoramidites to incorporate a useful hydrazine moiety at the 5’-end of an oligo for use with post-synthesis covalent attachment chemistry. 

Thiol modifiers

Thiol groups are often used to attach labels, such as fluorescent tags and biotin. Conjugation to a thiol is orthogonal to that of an amino functionality; it is not uncommon to have both groups in the same oligo (e.g., 3’-amino and 5’-thiol).

Thioctic acid is particularly useful for conjugating an oligo to gold and silver nanoparticles, making it important for biosensing technologies and self-assembling DNA applications.