Chapter 1 Introduction: An Overview of Microbiology and Cell Biology Postulate 1 organism should be preser in all cases of the diseas blood and absent from healthy animEs Suspecter Red blood cell Postulate 2 Streak agar plate with sample from ethe should be grow dIseased or healthy animal Colonie Inoculate healthy imal with cells suspected pathogen Postulate 3 Cells from n pute culture should cause disease in a Diseased ove blood or e sample and arve by microscopy Postulate 4 The organism should be Laboratory ed and show culture Figure 1.22 Koch's postulates for prov o original lowing isolation of a pure culture of the st Suspected pathogen Pure culture pected pathogen, a laboratory culture of th organism organism should both initiate the disease ar