Popular internet search engine Google on Friday celebrated German bacteriologist Julius Richard Petri's 161st birthday with an animated doodle showcasing his invention, the Petri dish.
In the doodle, netizens could see six colourful Petri dishes laid out in a row.
If an internet user clicks on the doodle then a gloved hand appears in the doodle which stirs the dishes.
Later, microbes grow on the dishes and they spell out the Google letters.
The dishes showed bacteria present in smelly socks, a door knob, keyboard, pet dog, plant, and a wet sponge.
All these animated elements could be seen when netizens moved their mouse cursors over the dishes .
Born on May 31, 1852, Petri is generally credited with inventing the Petri dish while working as assistant to Robert Koch.
Petri first studied medicine at the Kaiser-Wilhelm-Academy for Military Physicians and received his medical degree in 1876.
He continued his studies at the Charite' Hospital in Berlin and was on active duty as a military physician until 1882.
From 1877 to 1879 he was assigned to the Imperial Health Office in Berlin, where he became an assistant to Robert Koch.
On the advice of Angelina Hesse, the New York-born wife of another assistant, Walther Hesse, the Koch laboratory began to culture bacteria on agar plates. Petri then invented the standard culture dish, or Petri plate, and further developed the technique of agar culture to purify or clone bacterial colonies derived from single cells.
This advance made it possible to rigorously identify the bacteria responsible for diseases.
From Charlie Chaplin to Marie Curie, Google doodles not only celebrate birth anniversaries of great personalities, they also make users know about important dates through designs and animations.