The postulates were formulated by Robert Koch and Friedrich Loeffler in 1884 .
Date unknown : Koch 's postulatesare four criteria designed to establish a causative relationship between a microbe and a disease .
The postulates were formulated by Koch   and Friedrich Loeffler in 1884 .
Date unknown : Koch 's postulatesare four criteria designed to establish a causative relationship between a microbe and a disease .