This book on Molecular Biotechnology is divided in two volumes and contains five sections. Volume I contains 1 to 16 chapters and Volume II has 17 to 28 chapters. Volume I discusses Molecular biotechnology: A review, DNA, RNA and protein, recombinant DNA, manipulation of gene expression in prokaryotes and eukaryotes, heterologous protein production in eukaryotic cell, directed mutagenesis and protein engineering, molecular diagnostics, therapeutic proteins, nucleic acid based therapeutic agents, vaccines, synthesis of commercial products by recombinant micro-organisms, plant growth promoting bacteria, bio-pesticides and insecticides, large-scale production of enzymes by fermentation. The unique feature of this book is the chapters on bioinformatics, genomics and proteomics, bioremediation and biomass utilisation. Volume II discusses genetic engineering of plants, engineering plant quality and proteins, mobile DNA, molecular phylogenetics, nanotechnology in medical diagnosis, societal issues of biotechnology, bioethics and biosafety, regulating the use of biotechnology. The unique feature of this book is the chapters on transgenic plants and animals, molecular markers, nanotechnology in cancer diagnosis and treatment.