Koch's Postulates and Pure Cultures
Robert Koch grew single kinds of bacteria on solid jelly and proved that one germ causes anthrax, tuberculosis and cholera; his rules became the test for whether a microbe causes a disease.
Open in the interactive tree →In 1876 Koch showed that the anthrax bacillus causes anthrax, and in 1881 he presented plating on a solid nutrient medium, soon made with agar (an idea credited to Walther Hesse's wife Fanny), which gives pure cultures of one germ. On 24 March 1882 he announced the tuberculosis bacillus and in January 1884 he isolated the cholera bacterium; in 1884 Koch and Friedrich Loeffler set down the four criteria now called Koch's postulates. Pure cultures let researchers study one microbe at a time, and Koch's students included Emil von Behring and Shibasaburo Kitasato (antitoxin serum) and Paul Ehrlich (Salvarsan).
Prerequisites
- Microscope1665The germs were stained and studied under the microscope.
- Synthetic Dyes (Mauveine)1856Koch made bacteria visible by staining them with new aniline dyes.
- Germ Theory1861Koch set out to prove which germ causes which disease.
- Abbe Diffraction Limit (Microscopes)1873Zeiss oil-immersion lenses and Abbe's condenser made single bacteria visible.
Unlocks
- Antibodies and Serum Therapy1890Behring and Kitasato were Koch's students and worked with pure cultures of single germs.
- Antibiotics1928Pure cultures on plates are how germ-killing substances are found and tested.
- Streptomycin (First TB Antibiotic)1943-1952The tuberculosis germ had to be grown in the lab to test drugs on it.
- Helicobacter pylori and Ulcers1982Marshall and Warren cultured the stomach germ and held it to Koch's rules.
- Eradicating TuberculosisopenKoch identified the tuberculosis bacillus in 1882, the base of TB diagnosis.
Sources
More in Medicine · Industrial Age
- Smallpox Inoculation1721
- Vaccination1796
- Stethoscope1816
- Anesthesia1846
- Epidemiology1854
- Cellular Pathology (Virchow)1858
- Sewers and Clean Water1858
- Germ Theory1861