Agar, Petri Dishes, and Bacteria

You may be wondering where you can buy petri dishes with agar, or maybe even: "What is agar?” and "How do I use a petri dish?" Good news—you're in the right place. Pick the Biology lab supplies and the prices that are right for you! We provide a variety of reusable and disposable petri dishes, including plastic petri dishes, glass petri dishes, and polystyrene petri dishes. Shop complete kits, prepared agar plates, and a variety of Biology lab equipment & read free project ideas. We can help you create the perfect bacteria experiment for your kids—at home or in the lab.

See our Illustrated Bacteria Project Guide for tips and ideas!

So what is agar? It's a gelatinous medium providing nutrients and a stable controlled environment for bacteria growth. Most bacteria will grow well using nutrient agar, but some more fastidious bacteria prefer tryptic soy agar.

To prepare agar plates, just heat and pour into one of your selected sterile petri dishes. Next, collect bacteria: Swab along any surface to test (your mouth, the bathroom counter, etc.). To culture your microbes, lightly smear the swab in a zig-zag pattern on the surface of the agar plates. Within 1-2 weeks, you should see signs of bacterial growth.

Now you know where to buy petri dishes. But maybe you’re unsure what to add to your cart. We can help with your order!

• The bestselling Bacteria Growing Kit sets you up with all you need for 20 petri plates (even a step-by-step guide) in one easy set.
• For further microbiology study, the Gram Stain Kit has everything to test a bacteria sample. Just add bacteria + a microscope!

”We purchased this kit as a fun activity to supplement our regular science program. It came quickly, was high quality, and the kids really enjoyed the experiment.”
                —Customer Review (Bacteria Growing Kit)