2′,3′-Dideoxyguanosine (ddG) is a potent inhibitor of reverse transcriptase, used in the research of HIV. This biomolecule halts HIV replication by terminating the DNA chain during replication.

7-Deaza-dA and 7-Deaza-dG are isomers of A and G and have similar electron density. These modifed bases have been used for physical studies related to the interaction of enzymes and DNA as well as studies regarding the formation and structure of triplex DNA. 7-deaza purine monomers lack groups critical for hydrogen bonding.