N-(2-(2-(((Benzyloxy)carbonyl)amino)-6-oxo-1,6-dihydro-9H-purin-9-yl)acetyl)-N-(2-((tert-butoxycarbonyl)amino)ethyl)glycine is a peptide nucleic acid (PNA) that can be useful in APOE genotyping related to Alzheimer's disease, development of probes for Huntington DNA, and synthesis of cyclic PNAs targeting the HIV-??1 TAR RNA loop.