1. The specific organism should be shown to be present in all cases of animals suffering from a specific disease but should not be found in healthy animals.

2. The specific microorganism should be isolated from the diseased animal and grown in pure culture on artificial laboratory media.

3. This freshly isolated microorganism, when inoculated into a healthy laboratory animal, should cause the same disease seen in the original animal.

4. The microorganism should be reisolated in pure culture from the experimental infection.

In this exercise, Penicillium was utilized, a common, safe, mold. Certain species of Penicillium will spoil fruits, vegetables, grains, and grasses.

Some topics in this essay:
Materials Methods, Introduction Koch, Dextrose Agar, Postulates Blood, Koch’s Postulates, Discussion Questions, Results Macro-, AIDS HIV, Micro- Microscope, Laboratory Review, citrus fruits, koch’s postulates, penicillium italicum, sterile applicator, disease found, sterile applicator stick, pure culture, applicator stick, flame tube recap, penicillium digitatum, species penicillium, growth evident, penicillium italicum penicillium, tube recap discard, italicum penicillium digitatum,