The present textbook on DNA Recombinant Technology has been designed for university students, scholars and teachers dealing with genetics, molecular biology, genetic engineering, gene cloning, gene manipulation, microbiology and biochemistry. The overarching theme of the book the important link between genes and genetic engineering, is mirrored in the text. Efforts have been made to present the principles of recombinant technology, and its associated techniques, in sufficient detail to enable the non-specialist reader to understand them.