Recent research has produced a wealth of information on deoxyribonucleic acid sequences, their role in human disease, and their antimicrobial properties. This article discusses three aspects: (1) A new electrochemical technique has been developed for detecting DNA hybridization, determining DNA sequences, and identifying genes. (2) DNA helicase enzymes can mutate and lead to human disease. (3) A modified form of DNA that mimics transfer ribonucleic acid (tRNA) and can block tRNA binding has potential as a new type of antibiotic.