The two Essential Molecular Biology books in the Practical Approach Series are designed for the absolute beginner at gene cloning whether they be at the start of their career or an experienced researcher in another field. As with the first editions, the objective of both volumes is to combine solid practical information with sufficient background material to ensure that the novice can understand how a technique works, what it achieves, and how to make modifications to suit personal requirements. Volume 1 concentrates on the procedures for DNA and RNA manipulation: purification, electrophoresis, and the construction and cloning of recombinant molecules. It also includes a general introduction to molecular biology in the laboratory and a survey of cloning vectors for Escherichia Coli.