The enormous advances in molecular biology that have been witnessed in. Not recent years have had major impacts on many areas of the biological sciences least of these has been in the field of clinical bacteriology and infectious disease. Molecular Bacteriology: Protocols and ClinicalApplications aims to provide the reader with an insight into the role that molecular methodology has to play in modern medical bacteriology. The introductory chapter ofMolecular Bacteriology: ProtocolsandCli- cal Applications offers a personal overview by a Consultant Medical Microbio- gist of the impact and future potential offered by molecular methods. The next six chapters comprise detailed protocols for a range of such methods. We believe that the use of these protocols should allow the reader to establish the various methods described in his or her own laboratory. In selecting the methods to be included in this section, we have concentrated on those that, arguably, have greatest current relevance to reference clinical bacteriology laboratories; we have deliberately chosen not to give detailed protocols for certain methods, such as multilocus enzyme electrophoresis that, in our opinion, remain the preserve of specialist la- ratories and that are not currently suited for general use. We feel that the methods included in this section will find increasing use in diagnostic laboratories and that it is important that the concepts, advantages, and limitations of each are th- oughly understood by a wide range of workers in the field.