Glen Research’s interest lies in the preparation of caged oligonucleotides whose function is restored after uncaging by UV light at a wavelength that causes no DNA damage. The Deiters group at North Carolina State University has described NPOM-Caged-dT, where the nucleobase is caged with the photolabile group, 6-nitropiperonyloxymethyl (NPOM), which can be removed using UV light at 365nm. Oligonucleotides containing NPOM-Caged-dT every five or six bases do not hybridize to their complementary strand. Photo-uncaging of the caged oligonucleotide is then easily carried out with UV light at 365 nm for seconds to minutes to restore the activity of the oligonucleotide.