Microbial diversity is becoming a major topic of emphasis in the study of microbiology. This laboratory manual intended as an adjunct to the author''s Physiology and Biochemistry of Prokaryotes (OUP 1995) can also be used in conjunction with other books. The only laboratory manual available for the study of microbial physiology it includes about 18 experiments. Reagents and organisms are all readily available and the experiments have been polished and tested over several years of practice.