A process for deoxyribonucleic acid (DNA) sequencing, mapping, and diagnostics which utilizes the differences between the chemical composition of DNA and that of peptide nucleic acids (PNAs) to provide DNA sequencing, mapping, or diagnostics using natural DNA fragments, rather than using radioisotopes, stable isotopes or fluorescent substances to label the DNAs. The process includes the steps of hybridizing PNA segments to complementary DNA segments which are fixed to a hybridization surface, or hybridizing DNA segments to complementary PNA segments which are fixed to a hybridization surface, and using mass spectrometric or non-mass spectrometric techniques to analyze the extent of hybridization at each potential hybridization site.