Episode Details

Robert Koch rose from a rural German district physician working with a microscope his wife gave him for his birthday to a founding father of microbiology. This episode traces how he linked anthrax to a single bacterium, uncovered its resilient spores, and helped dismantle the miasma theory of disease.

We also follow the darker side of his career: the secretive 1890 tuberculin announcement that harmed patients, his feud with Louis Pasteur, his refusal to accept that bovine TB threatened humans, and his grudge-driven role in the 1902 Nobel malaria decision. Yet his methods endured, and tuberculin itself later became the basis of the Mantoux skin test.

• How oil immersion lenses, microphotography and Fanny Hesse's agar made pure bacterial cultures possible
• The March 24, 1882 announcement proving tuberculosis is caused by a specific pathogen
• Koch's postulates and the cholera research that exposed their limits
• Why the tuberculin cure triggered deadly immune reactions and damaged Koch's reputation
• How a failed treatment became a century-long diagnostic standard for TB exposure