Mike, Martin, Mike and Jon express their deepest gratitude to all the many individuals who have supported the creation of this 4th Edition (4E) of Nucleic Acids in Chemistry and Biology. We unhesitatingly give pride of place to our 21 co-authors, four of whom have continued their activity from an earlier edition. Without their commitment and dedication to delivering superb chapters to exacting editorial standards of presentation and style, 4E could not have achieved its cohesion and integration of contents that typified previous editions of this book.

The management and production team at the Royal Society of Chemistry merit our fulsome thanks. They have been led by the indefatigable Drew Gwilliams, whose unabated drive and support of this 4th Edition from start to finish and his tolerance of the vicissitudes of the four editors has led to its timely production. He has been ably supported by Polly Wilson, Liv Towers and Katie Morrey in production, editing and administration while our new commanding book cover was delivered by Connor Sheppard and Caroline Morley. We especially thank Professor Patrick Cramer (MPI Göttingen) for endorsing our use of his beautiful structure of a Replication Complex for the front cover, derived from PDB structure 6GMH. We are indebted to Richard Roberts and Marvin Caruthers for their enthusiastic endorsement on the back cover and in the Foreword.

We are very grateful to the many colleagues and scientists who have provided us with valuable comments, have read portions of the text of this latest edition, and have supported our writing through helpful discussions. They include Tom Brown, Per Bullough, Darryl Conte Jr, Livio Dukaj, Bill Earnshaw, Jamie Hobbs, John Kozarich, Brian Kelch, Li Li, Anna Loveland, Alfonso Mondragon, Makoto Ohira, Mary Pickering, Ollie Rando, Sam Roberts, Erik Sontheimer, Chris Smith, Katherine Stott, Jussi Taipale, Song Tan and Dan Wang while many of our students have also assisted us in diverse ways.

This edition has made even greater use of full colour than its predecessors. Much of that has benefitted from the efforts of co-workers who have assisted in the production of numerous eye-arresting illustrations. They include Benjamin Ambrose, David Boykin, Hao Chen, Joseph G. Gall, Philip Haynes, Adam Hedger, Yi Jin, Brian Kelch, Kavit Main, Celeste Molt, Irina Parfenova and Wen Zhu to whom we accord our sincere thanks. Among the providers of software that has been employed for this purpose, we particularly acknowledge the PyMOL Molecular Graphics System, Version 1.2r3pre, Schrödinger, LLC. Use has also been made of UCSF Chimera, developed by the Resource for Biocomputing, Visualization, and Informatics at the University of California, San Francisco, with support from NIH P41-GM103311.

We have enjoyed receiving a large number of positive, helpful and corrective comments from readers of the first three editions, which we have sought to incorporate into this expanded 4th Edition. Nonetheless, despite our careful work, it is unavoidable that there will be errors in this volume for which we accept full responsibility. Finally, we look forward to your advice, opinions, and suggestions for a fifth edition – which will become inevitable in due course!