The structure, function and reactions of nucleic acids are central to molecular biology and medicine, and are crucial for understanding the ever-expanding range of complex biological processes central to life. Revised, extended, updated and lavishly illustrated, this 4th Edition of Nucleic Acids in Chemistry and Biology is a long-awaited standard text for teaching and research in nucleic acids science. It maintains the close integration of chemistry and biology that characterised three earlier editions while it embraces a major expansion strongly focused on the burgeoning growth of RNA science. Written by an international team of leading experts, all with extensive teaching experience, this 4th Edition provides up-to-date and extended coverage of the interface of chemistry and biology in the study of nucleic acids. A brief history of the discovery of nucleic acids leads into a molecule based introduction to the structure and biological roles of DNA and RNA. New chapters reflect the progress in Non-coding RNA, Next Generation Sequencing, Nucleic acid Therapeutics, in vitro Evolution and Aptamers. This new Edition maintains, expands, and updates its strong coverage of the reactions and interactions of RNA and DNA with enzymes, binding proteins and drugs, and therapeutic work directed to combat Covid-19. This New Edition presents topics in an integrated manner and readable style with full colour illustrations throughout. It has a large list of citations that make it a definitive reference source. It is focused on introducing this subject to graduate and advanced undergraduate students of chemistry and biochemistry, biophysics and biotechnology, molecular biology and medicine. It will continue to be the 'Laboratory Bible' for new researchers to the field of nucleic acids science.