Enhanced public awareness of microbiological issues and increased governmental regulation have ensured that microbiology and bacteriology remain important, from the academic laboratory to a broad range of indus trial environments. Since the techniques used in bacteriology vary widely and have advanced rapidly of late, it has become increasingly desirable to gather a collection of up-to-date protocols from a comprehensive range of disciplines into a single volume. Diagnostic Bacteriology Protocols thus aims to provide a wide variety of up-to-date protocols for the identification and differentiation of bacteria from pure or mixed cultures, and for the study of bacteria at the genus through to subspecies levels. In addition, we aim to provide methods covering a range of complexities, some requiring little or no special equipment, others exploiting recent advances in sophisticated instrumentation or novel nucleic acid-based technology. We also present techniques to study a variety of aspects of bacteria—from the features of whole cells and their growth, through their enzyme activities and structural components, to nucleic ac- based analysis.