ROBERT KOCH

                                         

Heinrich Hermann Robert Koch(1843-1910), German physician and microbiologist was one of the main founder of the modern Bacteriology.

He is well known for his "Koch's Postulates" which is used for the identification of the causative agent for infective diseases.

KOCH POSTULATE :

• The bacterium should be constantly associated with the lesions of the disease.
• It should be possible to isolate the bacterium in pure culture from the lesions.
• Inoculation of such pure culture into suitable laboratory animals should reproduce the lesions of the disease.
• It should be possible to re-isolate the bacterium in pure culture from the lesions produced in the experimental animals.

Later in ages, 5th criterion was added to this, which states that,

• Antibody for the causative organism should be demonstrable in the patient's serum.

Thus by fulfilling all these criterions stated above, a microorganism can be regarded as a causative agent of an infective disease. 

EXCEPTIONS :

There are some bacteria that do not satisfy one or more of the four criteria. 

Examples -  Mycobacterium leprae and Treponema pallidum as they cannot be grown in vitro.

OTHER CONTRIBUTIONS :

1. He introduced solid media by using Agar as solidifying agent.
2. Introduced methods for isolation of bacteria in pure culture.
3. Discovered bacteria's - Anthrax bacilli, Tubercle bacilli, cholera bacilli.
4. He described Hanging Drop technique for testing bacterial motility.
5. Introduced staining techniques by using aniline dyes.
6. He described Koch's phenomenon.