This book is exactly what it claims to be--a laboratory guide. It provides methods that are clear, but also explains the reasons for the methods. For example: when is an RNA probe better than a DNA probe and why; when nonisotopic labels can be used effectively. Although there is not a chapter on in situ hybridization, I found the section on probes very helpful. There is also a handy glossary at the end and a primer on RNA at the beginning of the book. Dr Farrell realizes the reader maybe new to the field and so doesn't leave out the basics. However, I believe this book will be helpful to all but the most knowledgable molecular biolgists.