Born in 1852 in Barmen, Germany, Petri received his medical degree from Berlin's Kaiser-Wilhelm Academy for Military Physicians in 1876. For the following two years, he worked in the Imperial Health Office in Berlin, where he became an assistant to Robert Koch.
It was there that he invented the Petri dish, a shallow glass container that biologists use to culture cells. The dish helps scientists grow bacterial cultures and identify many bacteria responsible for various diseases.
Today's Google Doodle shows six petri dishes. Move the mouse over each one to identify the source of the bacteria within: a smelly sock, a door knob, a computer keyboard, a dog, soil near a plant and a kitchen sponge.
Which Google Doodle has been your favorite so far? Share your thoughts in the comments!