Petri Dish Emoji

A shallow, circular laboratory dish with a lid, containing splotches of colorful bacteria or cell cultures growing on agar. This is the petri dish: the single most important tool in the history of microbiology, the vessel where Alexander Fleming accidentally discovered penicillin, and the object that made it possible to study bacteria at all.

As an emoji, 🧫 lives a quieter life. It shows up in conversations about biology, lab work, scientific research, and microbiology. Students use it when posting about coursework. Researchers throw it into tweets about experiments. Biotech companies sprinkle it into announcements alongside 🧪 and 🔬.

But the most interesting use is metaphorical. "Social petri dish" has become a common expression meaning a contained environment where something is growing or being observed. A reality TV house is a petri dish. A startup incubator is a petri dish. During COVID-19, entire cities were described as petri dishes. The emoji carries that same energy: controlled growth, careful observation, something multiplying under watch.

🧫 is a niche emoji. You won't see it in most group chats or caption copy. Its home is science communication: lab selfies, biology memes, research threads, and biotech marketing. It pairs naturally with the rest of the science emoji family that arrived in Unicode 11.0 (2018).

The petri dish saw a small bump during the COVID-19 pandemic, when lab imagery dominated the news and the 🦠 microbe emoji experienced 800% growth on Twitter in 2020. But while 🦠 became shorthand for the virus itself, 🧫 stayed in the background as the tool, not the star.

On TikTok and Instagram, it appears in the #AgarArt niche, where microbiologists create actual paintings using living bacteria in petri dishes. The American Society for Microbiology's annual Agar Art Contest received 557 submissions in 2025 and has been covered by over 200 media outlets including National Geographic. These posts often stack 🧫🎨🦠 together.

Outside science circles, people occasionally use 🧫 to mean "something brewing" or "watching this develop," treating the petri dish as a metaphor for slow, visible growth.

The petri dish is named after Julius Richard Petri (1852-1921), a German microbiologist working as an assistant to the legendary bacteriologist Robert Koch at the Imperial Health Office in Berlin. In 1887, Petri published a modest note titled "A Small Modification of the Plating Technique of Koch," describing a simple improvement: instead of pouring culture medium onto a glass plate and covering it awkwardly, he placed the medium directly into a shallow glass dish with a snug-fitting lid.

The improvement sounds trivial. It wasn't. Before Petri's dish, working with bacterial cultures meant constant contamination risk. The lid kept airborne contaminants out while still being small and flat enough to slide under a microscope. Koch's lab adopted it immediately, and within years it became standard worldwide.

Historians note that the idea wasn't entirely unique. A 2019 study in the Journal of Medical Microbiology called it "a case of simultaneous invention," with half a dozen bacteriologists developing similar flat culture dishes in the mid-1880s. But Petri published first, in association with Koch's prestigious institute, and so the name stuck.

The dish's most famous moment came 41 years later. On September 28, 1928, Scottish bacteriologist Alexander Fleming returned from a two-week vacation to find a petri dish of Staphylococcus bacteria contaminated with a mold. Around the mold, the bacteria had died. Fleming identified the "mold juice" as a substance from Penicillium notatum and named it penicillin. That contaminated dish launched the antibiotic revolution and earned Fleming the 1945 Nobel Prize in Physiology or Medicine. The original petri dish is now held at the British Museum.

Approved in Unicode 11.0 (2018) as part of a batch of nine science emojis: lab coat, goggles, test tube, petri dish, DNA, microbe, compass, abacus, and fire extinguisher. The proposal (L2/17-113) was drafted at Emojicon 2016 in San Francisco by a group including representatives from the American Chemical Society, with C&EN product manager Jessica Morrison helping write it. The International Council for Science and the American Geophysical Union helped determine which emojis to submit. Several proposed science emojis were rejected, including a molecule (too hard to pick which one), an atom, a rock, and a Geiger counter.

1. 1887Julius Richard Petri publishes his flat culture dish design while working in Robert Koch's lab in Berlin↗
2. 1928Alexander Fleming discovers penicillin growing in a contaminated petri dish, launching the antibiotic era↗
3. 2015American Society for Microbiology launches the Agar Art Contest, turning petri dishes into canvases↗
4. 2016Science emoji proposed at Emojicon San Francisco by ACS group, including petri dish, DNA, test tube, and microbe↗
5. 2018Unicode 11.0 approves 🧫 Petri Dish along with eight other science emojis↗
6. 2020COVID-19 pandemic brings lab imagery into mainstream culture; science emojis see usage spike on social media↗

• •Penicillin, discovered in a petri dish in 1928, has saved an estimated 200 million lives since its mass production began in the 1940s.
• •The petri dish was designed in 1887, but the concept of growing bacteria in flat containers was independently invented by at least six different bacteriologists in the same decade.
• •Alexander Fleming, the discoverer of penicillin, was also the original agar artist. He would create paintings using pigmented bacteria in petri dishes long before the ASM made it a formal competition.
• •The 🧫 emoji arrived in 2018 as part of Unicode 11.0, in a batch of nine science emojis proposed by scientists at Emojicon 2016. A molecule emoji was rejected because the committee couldn't agree on which molecule to depict.
• •During COVID-19, the 🦠 microbe emoji grew 800% on Twitter, appearing in roughly 1 of every 500 tweets. The petri dish emoji, its lab partner, stayed in the background.
• •In Google Trends, "petri dish emoji" registers near zero search interest since 2018, while "DNA emoji" scores 89. It's the most historically significant but least searched science emoji.
• •Samsung's version of the petri dish emoji includes a lid. Google's earlier design featured a dropper hovering above it. Most platforms show it as a clear, shallow cylinder with colorful bacterial splotches.
• •The word "petri dish" has become a common English metaphor meaning a breeding ground or controlled environment. Calling a place a "petri dish for corruption" implies something is growing unchecked.
• •Viral petri dish photos comparing bacterial growth from coughing with and without a mask were among the most-shared science images of the COVID-19 pandemic.

• •Alexander Fleming's contaminated petri dish where he discovered penicillin in 1928 is preserved as a historical artifact, arguably the most consequential petri dish in human history.
• •Since 2015, the ASM Agar Art Contest has invited microbiologists to create paintings using living organisms in petri dishes. Alexander Fleming himself was the original agar artist, decades before the competition existed.
• •The petri dish was one of 9 science emojis born from a group of scientists and ACS representatives at Emojicon 2016 in San Francisco. Rejected siblings included a molecule (couldn't agree which one) and a Geiger counter.