Copper-free "click" modification of DNA via nitrile oxide-norbornene 1,3-dipolar cycloaddition.

Nitrile oxides react smoothly and rapidly with norbornene-modified DNA in a copper-free click reaction. The reaction allows high density functionalization of oligodeoxyribonucleotides (ODNs) with a large variety of molecules directly on solid supports and even in synthesizers without the need for an additional catalyst.

Postsynthetic DNA modification through the copper-catalyzed azide-alkyne cycloaddition reaction.

The attachment of labels onto DNA is of utmost importance in many areas of biomedical research and is valuable in the construction of DNA-based functional nanomaterials. The copper(I)-catalyzed Huisgen cycloaddition of azides and alkynes (CuAAC) has recently been added to the repertoire of DNA labeling methods, thus allowing the virtually unlimited functionalization of both small synthetic oligonucleotides and large gene fragments with unprecedented efficiency. The CuAAC reaction yields the labeled polynucleotides in very high purity after a simple precipitation step.

Synthesis of modified DNA by PCR with alkyne-bearing purines followed by a click reaction.

Alkyne-bearing deazapurine triphosphates were prepared and successfully incorporated into DNA using the polymerase chain reaction (PCR). The obtained alkyne-labeled DNA was successfully used in a click reaction with galactose azide.