In the middle of the twentieth century, medical technologists and clinical pathologists were expected to maintain expertise in all aspects of the service laboratory; most were poorly trained in diagnostic microbiology. With the widespread use of antimicrobial chemotherapy, the nature of infectious diseases gradually changed and that created new challenges to those concerned with the diagnosis and treatment of infectious diseases. Consequently, clinical laboratories were being asked to perform increasingly sophisticated procedures. To help clinical pathology laboratories meet those new challenges, a number of industries were developed to provide supplies and equipment that laboratorians could no longer make or obtain for themselves. Standardization of methodology was essential for such commercial endeavors to be successful. Performance standards were needed in order for each laboratory to judge the quality of different products. Regulatory agencies were also being asked to monitor the quality of products being sold to diagnostic laboratories. Government agencies were being forced to provide standards for judging the quality of different reagents and equipment; for obvious reasons, laboratory professionals wanted to be involved in writing such standards.