A short textbook reviewing the principles and methods employed in the laboratory for antimicrobial susceptibility testing. The first section reviews the advantages of various procedures and discusses the theoretical basis of susceptibility testing. A chapter on the definition of antibiotic susceptibility puts the problem of interpretation of the terms sensitive and resistant into prospective with clarity and precision. The rest of the book is largely a presentation of the methods used to assay various species of bacteria for their antibiotic sensitivity, the development of standards, and the interpretation of results. Recommended for microbiology laboratories, hospital libraries, and infectious disease specialists.