Julius Richard Petri (Barmen, May 31, 1852 – Zeitz, Germany, December 20, 1921) was a german microbiologist who is credited with inventing the Petri dish whilst working as an assistant to Robert Koch¹.
After primary and secondary education, he studied medicine at the Kaiser Wilhelm-Akademie for military physicians between 1871 and 1875. He completed his doctorate as a physician at the Charité in Berlin, which he obtained in 1876. Between 1876 and 1882 he served as a military doctor and was an assistant to Robert Koch (Nobel Prize in Physiology and Medicine in 1905), and it was whilst working with the famous German scientist when he invented his famous petri dish in 1877. Basically it joined two round clear glass covers that allowed samples to isolate different organisms and allowed them to grow in controlled conditions. Petri designed a container about ten centimeters in diameter with edges of 1 to 1.5 cm high. This allowed the molten to extend over a large area of 0.5 to 0.7 cm thick agar.
What seemed simple and currently more than normal, at the time but it was a revolution for microbiology and medicine.
For the nineteenth century highly contagious epidemics were declining population of half the world. Thanks to the petri dishes, they were able to isolate microorganisms that caused diseases such as diphtheria or cholera, then finding the cure thereof. Until that time the cultures were made by melting the solid agar media and then extending on one side of a test tube. This made it difficult to obtain separate colonies and studied so few extensions.
The petri dish, widely used in microbiology studies to culture microorganisms