Google honoured Nobel-winning German physician and microbiologist Robert Koch with a doodle on Sunday. Koch was awarded the Nobel Prize in Physiology or Medicine on December 10, 1905, “for his investigations and discoveries in relation to tuberculosis”.

Apart from tuberculosis, Koch played a key role in identifying the bacterium for anthrax and cholera also. He set guidelines and principles linking microorganisms with specific diseases. His four-point guidelines are considered the golden rules in medical microbiology.

Born on December 11, 1843, Koch studied medicine at the University of Göttingen. He started his career by working as a district medical officer at Wollstein. The Nobel laureate experimented with potato slices to isolate pure bacterial cells to help with his research. Later, his assistant Julius Petri invented the Petri dish that made observing bacteria easier.

The doodle by Sophie Diao features potato slices as well as Petri dish.