This text gives a broad, but concise, coverage of gene cloning and manipulation, suitable for undergraduates and beginning graduate students. Assuming only general biochemical knowledge, it stresses the concepts underlying particular types of cloning vector, and uses examples to illustrate them, rather than simply presenting a mass of detailed lists and vector maps. The book starts by describing the principles behind cloning DNA in E. coli, the enzymes used, the range of cloning vectors available, and how to screen libraries to find particular clones. The author shows how PCR can be used as an alternative, or complementary, approach. He then goes on to describe how sequences can be exploited, after cloning and identification, by site-directed mutagenesis and over-expression. The book finishes with a detailed presentation of the genetic manipulation of other organisms, including other bacteria, yeast, plants, insects, and mammals.