Alkynes readily react with azides in the presence of copper to form stable triazole bonds, the basis for click chemistry. IDT offers several modifications used in click chemistry:
Hexynyl is used to introduce a 5′ terminal alkyne group.
5-Octadiynyl dU is a modified base with an 8 carbon linker terminating in an alkyne group. This modified base is preferred when inserting alkynes at internal positions within a sequence.
Azide NHS Ester leaves a free azide group available to click with a free alkyne.
Also inquire about using a 3’Alkyne Modifier, as well as DBCO used for copper-free click chemistry.
Read more about click chemistry in the DECODED article, Oligo Modification—Post-Synthesis Conjugation Explained