We must unashamedly admit that a large part of the motivation for editing Genomics Protocols was selfish. The possibility of assembling in a single volume a unique and comprehensive collection of complete protocols, relevant to our work and the work of our colleagues, was too good an opportunity to miss. We are pleased to report, however, that the outcome is something of use not only to those who are experienced practitioners in the genomics field, but is also valuable to the larger community of researchers who have recognized the potential of genomics research and may themselves be beginning to explore the technologies involved. Some of the techniques described in Genomics Protocols are clearly not restricted to the genomics field; indeed, a prerequisite for many procedures in this discipline is that they require an extremely high throughput, beyond the scope of the average investigator. However, what we have endeavored here to achieve is both to compile a collection of procedures concerned with geno- scale investigations and to incorporate the key components of "bottom-up" and "top-down" approaches to gene finding. The technologies described extend from those traditionally recognized as coming under the genomics umbrella, touch on proteomics (the study of the expressed protein complement of the genome), through to early therapeutic approaches utilizing the potential of genome programs via gene therapy (Chapters 27-30).