Petri first studied medicine at the Kaiser-Wilhelm-Academy for Military Physicians (1871–1875) and received his medical degree in 1876. He continued his studies at the Charité Hospital in Berlin and was on active duty as a military physician until 1882, continuing as a reservist.
From 1877 to 1879 he was assigned to the Imperial Health Office (German: Kaiserliches Gesundheitsamt) 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.
On May 31, 2013, Google created an animated doodle in his honor to commemorate his 161st birthday. The doodle consisted of six animated petri dishes. As the cursor passes over each petri dish, it showed the source of the dish's contents: smelly socks, a door knob, a computer keyboard, a drooling dog, a plant in the rain, and a dish being washed.
- The Independent, Newspaper. "Google Doodle commemorates Julius Richard Petri - inventor of the [[Petri dish]] - on what would have been his 160th birthday". Article. http://www.independent.co.uk. Retrieved 31 May 2013. Wikilink embedded in URL title (help)
- "Today Google is celebrating the life and legacy of Julius Richard Petri the inventor of the Petri Dish". Scribd.
- "Julius Richard Petri: Google celebrates birth of inventor of the petri dish". guardian.co.uk. 30 May 2013. Retrieved 2013-5-30.