There is a hypothesis that chytrids are responsible for massive die-offs currently occurring in amphibians. Review Koch's postulates; then design a study showing how you would use Koch's postulates to test the hypothesis that chytrid infections are responsible for the frog deaths.

Koch's postulates say that microbes are present in the case of every disease and these disease-causing microbes can be isolated to grow in pure culture. He also said that this pure culture if transferred in healthy individual it will cause disease.

Chytrids contain many parasite fungus that infects amphibians and by using Koch postulate we can show that chytrid infections are responsible for the frog deaths.

First, we have to take the sample from dead diseased amphibian then this sample should be inoculated in a selective media which supports the growth of chytrid fungus and not bacteria.

Then this pure culture of fungus is transferred in a healthy amphibian. The death from chytrid infection of healthy amphibian will show that chytrid infections are responsible for the frog deaths.