Attach modifications after oligo synthesis using Azide (NHS Ester)

Need to perform a click chemistry reaction? Start with an azide-modified oligo from IDT, to which you can add alkyne modifications, post-synthesis, in either copper-mediated or copper-free click reactions. Order Azide NHS (Ester) and other modifications from IDT. We will consider any requests.

May 15, 2017

Quick facts: Azide (NHS Ester)

Availability: DNA and RNA

Location: 5', internal, 3'

Scales: 100 nmol to large scale

Purification: HPLC

IDT ordering symbol: /5AzideN/, /iAzideN/, /3AzideN/

A standard oligonucleotide modification available from IDT, Azide (NHS Ester) provides a reactive site for attachment of alkyne groups to an oligo (Figure 1) through a copper-catalyzed, click chemistry reaction (Figure 2). Several types of modifications are commercially available for conjugation to an azide-modified oligo; these include ferrocene and 5/6 TAMRA. Alternatively, you can add a strained alkyne modification, such as DBCO (dibenzocyclooctyl), DIBO (dibenzocyclooctyne), or BCN (bicyclo[6.1.0]nonyne), to the azide modified oligo using a copper-free click reaction.


Figure 1. Azide (NHS Ester).


Figure 2. Azide click chemistry reaction. This copper catalyzed reaction between an azide group and an alkyne group produces a 1,2,3-triazole. IDT attaches a variety of modifications post-synthesis using this click chemistry reaction.

Ordering your azides

At IDT, we incorporate azides into oligos after synthesis, using NHS ester chemistry. An amino modification, added during oligo synthesis, is used in the NHS ester reaction. For example, a 5' azide is attached to the oligo sequence through a 5' Amino Modifier C6, while a 3' azide is attached through a 3’ Amino Modifier. An internal azide is attached through the Amino Modifier C6 dT, which results in the incorporation of a dT base at that location in the oligo sequence. When you order, you need only specify the Azide (NHS Ester) modification in your sequence; we will automatically add the necessary amino modifier.

To order, add the necessary ordering symbol (/5AzideN/, /iAzideN/, or /3AzideN/) in the desired location within your sequence.

Note: oligonucleotides with Azide (NHS Ester) require HPLC purification.


Click chemistry reactions

Click chemistry is used to join small chemical subunits in a modular fashion, yielding a single reaction product that is typically physiologically stable and stereospecific. Most commonly, azide and alkyne groups are coupled in a copper-catalyzed reaction, forming a 1,2,3-triazole. This irreversible reaction is thermodynamically favorable and has no side products. There are also click chemistry reactions that do not require copper. For more information about click chemistry reactions, see the following DECODED articles: