Koch's Postulates Microorganisms are isolated from a dead animal. 。Koch's Postulates are used to prove Colony the cause of an The microorganisms are The microorganisms grown in pure culture. are identified. infectious disease. 3The microorganisms are injected into a healthy animal. Figure 14.3.1 • Koch's Postulates are used to prove the cause of an infectious disease. Koch’s Postulates Figure 14.3.1