As an introduction to this program's career, Lynn Poole notes that it was announced this week that the Salk vaccine is effective in preventing polio. He also points out that in 1890 Dr. M. Cary Thomas was only allowed to attend classes at Johns Hopkins University if she sat behind a screen because she was a woman in a men's institution. But this program features Isabelle Schaub, assistant professor of microbiology at that university and author of the Diagnostic bacteriology textbook. She introduces a number of young women and describes their laboratory job functions in the fields of bacteriology, biochemistry, hematology, serology, and histology. Brief film clips, from the National Committee for Careers in Medical Technology, show the processes of preparing slides of body tissues and studying blood cells under a microscope. Ms. Schaub lists three ways to enter the field: as an entry level lab aid, as a recipient of the American Society of Clinical Pathologists certificate, or as a college graduate.