The aim of this manual is to encompass a broad range of the latest plant molecular biology techniques. However, it is acknowledged that any manual will be read (and hopefully) used by a wide range of people with different levels of experience. Hence the remit of the manual was widened to include a full range of basic molecular tech­ niques, so that novices do not have to consult several texts to enable the execution of each major experiment. The manual is divided into three main parts: Part I: Basic Molecular Techniques The raison d'etre behind this part is to provide a background knowledge of molecular techniques, but also to reduce duplication in later chapters (this is particularly true of the methods contained in Chap. 1). All authors provided very detailed methods and often forgot that so me of these would be covered earlier. A particular favourite was DNA extraction methods, wherc everyone managed to provide a slightly different variant! My view was that it is far less confusing for the reader to be presented with one standard protocol and accom­ panying troubleshooting tips, than to read a different version in each chapter. In this way the basic techniques are addressed more in depth (and my apologies to all authors for judicious use of the delete key!). RNA methodology is covered in Chapter 3. This proceeds from the fundamentals of extraction, northern blotting etc. , to cDNA libraries.