FAQ
Common questions.
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The kit
What does the kit include?
Six pre-poured culture plates ready for air sampling, gloves, and instructions, plus a code that unlocks six plate analyses in the Petri Studio app. One analysis for each plate, with no extra purchase needed.
How do I collect a sample?
These are air settling plates. Open a plate and leave it out in the room you want to test for 1 to 2 hours, then close it. That captures what is settling out of the air. The app explains it step-by-step.
Does the kit test for both mold and bacteria?
Yes. The culture media supports growth of both mold/fungi and bacteria, and the app reads visible growth of both. Mold and fungal growth is the most visually distinctive, which is why it features prominently in results.
How long does incubation take?
3 to 5 days. Keep the plate closed at room temperature, and the app reminds you when it is ready to photograph. Warmer rooms (above 70°F) tend to show growth sooner.
The app and pricing
Do I need a Petri Studio kit to use the app?
No. If you already have a compatible settle plate from another brand, you can capture it in the app and get the same guided read of visible growth, saved to the room it came from.
How much does analysis cost for a plate from another brand?
Your first one is free. After that you buy analyses in the app, one at a time or in packs of 3 or 6, and the bigger packs cost less per plate. Current prices are in the Pricing section on our home page.
How often do I get a free analysis?
You get one free analysis of a plate from another brand every three months. If you still have unused analyses from a Petri Studio kit, use those first; the free one waits until they are done.
Is it a subscription?
No. Analysis packs and kits are one-time purchases. Nothing renews, and nothing is charged unless you choose to buy it.
Can I buy analysis packs on this website?
No. Analysis packs are sold only inside the Petri Studio app. This website sells the kit, and the kit already includes analysis for all six of its plates.
Which is better value, the kit or analysis packs?
If you need plates, the kit. It includes six plates and six analyses, so every plate in the box is already paid for. Analysis packs make sense when you already have plates from another brand.
Results
How reliable is the read?
Our model is trained on real plate photographs, and lab-grade culture media produces consistent colony growth for it to read. The result describes visible patterns on your plate and gives educational guidance. It is not species identification and not a certified lab diagnosis. If you need a confirmed species-level result for a legal or medical decision, use an accredited testing laboratory.
What does my result actually tell me?
A plain-language read of what is visible on the plate, with the limits stated: the kinds of growth it can see, a severity assessment (low, moderate, or high), and what to consider next, whether that's monitoring and retesting or looking into remediation. Each result is saved to the room it came from, so your next test has something to compare against.
What if nothing grows after 5 days?
A negative result — no visible growth — is a meaningful data point. The app will confirm this and explain what it likely means for your space. It does not guarantee the absence of all microorganisms, but it is a good sign.
How do I get my results?
Photograph the closed plate in the Petri Studio app. Your read appears in the app within seconds and is saved to the room and date it came from. A PDF report is available to download and share.
Accuracy & science
What kind of culture media do you use?
Our plates are pre-poured with lab-grade culture media formulated to support a broad range of environmental molds, fungi, and bacteria. The media formulation draws on the same standards used in regulated pharmaceutical and biotech quality control environments.
Is this a medical test?
No. Petri Studio kits are for informational use only. They are not medical devices and results are not a substitute for professional inspection, remediation, or medical advice. If you have health concerns related to mold exposure, please consult a licensed physician.
How does this compare to a professional inspector?
A professional inspector brings expertise, equipment, and in some cases regulatory standing that a consumer kit cannot replicate. We are not a replacement for a professional inspection in situations where one is warranted — after a significant water event, during a real estate transaction, or when health symptoms are present. We are a first step: an accessible, fast, and informative starting point that helps you decide whether professional follow-up is needed.
Orders & shipping
When will kits ship?
Kits ship once the Petri Studio app launches, so you have something to read your plates with the day they arrive. We have not set a date yet. Leave your email and you will hear it first.
Can I order a kit yet?
Not yet. Ordering opens when the app launches, and nothing on this site takes payment today. Leaving your email costs nothing, does not reserve a kit, and does not charge you.
What is the email signup for, then?
We email you the app link on launch day and tell you when kit ordering opens. It is not a reservation and it does not hold a kit for you.
Where do you ship?
United States only at launch. We're prioritizing the DC, Maryland, and Virginia region for our earliest testers, with national shipping following shortly after.
Can I return a kit?
Yes, within 30 days of delivery, as long as it is unopened. Email hello@getpetristudio.com with your order number and we will set it up. If a kit arrives damaged or turns out to be faulty, we cover it either way and there is nothing to send back. The full policy is on our Terms page.
Still have questions? We're happy to help.
Email hello@getpetristudio.com