Tuberculin, 1890

Robert Koch (1843?1910), who isolated Mycobacterium tuberculosis in 1882 and proved that it caused tuberculosis, announced at a medical congress in Berlin eight years later that he had developed a substance capable of preventing the growth of the tubercle bacilli, thus arresting the disease. He called this substance ?tuberculin,? while keeping its formulary secret. Actually, it was a glycerin-broth culture he used to grow M. tuberculosis, which he then evaporated to one-tenth its volume at 100ﾰ C before filtering. Within days, newspapers around the world announced that Koch had a cure for tuberculosis.