Laboratory Petri dishes: for which inoculation, isolation and observation applications are they used?

Essential for microbiological culture and cell culture, Petri dishes provide a flat, transparent and controlled surface for inoculation, isolation and observation. Available in single-use sterile polystyrene or reusable borosilicate glass, they come with vented lids (gas exchange) or non-vented, in 35 to 150 mm diameters, with TC-treated options for cell adhesion, and gridded or segmented versions for counting. Their flatness, optical quality and traceability ensure reproducible results in a laminar flow cabinet, incubator or automated systems.

What are the different types of Petri dishes?

Two main families structure the range: the Petri dish for microbiology and the Petri dish for cell culture.

For microbiology, clear polystyrene models, pre-sterilised (gamma-irradiated), dominate: perfectly flat bases for uniform agar thickness, snug-fitting lids with stacking lugs, versions with vents to limit condensation and ensure gas exchange. Common diameters: 90 mm (standard), 55/60 mm (targeted assays) and 120–150 mm (colony counting, observation). Options: gridded dishes for enumeration, plates with 2 or 4 compartments to inoculate multiple media in a single vessel.

For cell culture, TC-surface-treated polystyrene (oxidation/plasma) is preferred to promote adhesion of adherent lines. Low-profile lids and vents regulate CO?/O? exchange in the incubator. Low-attachment surfaces are available for spheroid/aggregate formation. Quality requirements: pyrogen-free, RNase/DNase-free, particle control, sterility certification.

Borosilicate glass dishes are autoclavable and chemically inert: suitable for special media, higher temperatures and waste-reduction workflows. Their mass and durability, however, require rigorous wash/sterilise management.

Key selection criteria: application (microbiology vs cells), material (PS/glass), diameter, lid ventilation, surface treatment (TC or not), presence of grid/compartments, sterility level and optical quality (imaging). Consider compatibility with CO? incubators, colony counters and airflow in microbiological safety cabinets (MSCs).

Summary comparison table:

Type	Principle	Applications
Microbiology (PS 90 mm, vented)	Poured agar, surface inoculation	Colony counts, antibiograms, hygiene monitoring
Cell culture (TC-treated PS)	Oxidised surface promoting adhesion	Line expansion, clonogenicity, imaging
Reusable borosilicate glass	Autoclavable, chemically inert	Special media, higher temperatures, waste reduction

On impact, favour reusable glass where appropriate, choose bulk packs to reduce packaging, and sort contaminated disposables according to your HSE procedures.

In which scientific fields is a Petri dish used?

• Microbiology and health: bacterial/yeast isolation, enumeration, antimicrobial susceptibility testing (AST), identification.
• Food & beverage: HACCP monitoring, surface hygiene, product and process water testing.
• Pharmaceutical & cosmetics: bioburden, environmental monitoring (cleanrooms), batch testing via filtration/inoculation.
• Environment & water: coliforms, enterococci, enumeration on selective media.
• Cell culture: expansion, clonogenicity assays, immunofluorescence, live/endpoint imaging on TC-treated or low-attachment surfaces.
• Education & R&D: practicals, screening, media optimisation.
• Automation: compatibility with colony counters, imaging systems and barcode-based traceability.

Available types of Petri dishes

Frequently asked questions about Petri dishes

What’s the difference between microbiology plates and cell-culture dishes?
Microbio: sterile PS for agar and colony growth. Cells: TC-treated surfaces promoting adhesion, CO?-optimised lids and optical-grade clarity for imaging.

Vented or non-vented: which should I choose?
Vented limits condensation and supports gas exchange; non-vented reduces evaporation. In a CO? incubator, favour vented lids and controlled humidity.

Which diameter for my applications?
90 mm is the standard for streaking and colony counting. 35–60 mm for targeted assays, 120–150 mm for extended observation; grids and partitions streamline series work.

Glass or polystyrene: impact and performance?
Borosilicate glass is reusable and inert, but requires sterilising. Sterile PS is ready to use, consistent and automation-friendly, at the cost of more waste.

What does the “TC-treated” label imply?
An oxidised/plasma-treated surface that increases hydrophilicity and cell attachment. Ideal for adherent cells; choose non-treated or low-attachment for suspension cultures/spheroids.

How to limit condensation on agar?
Use lids with vents, equilibrate media and dishes before pouring, avoid thermal shocks and stack sensibly to allow gentle airflow during incubation.

Are the dishes compatible with colony counters?
Yes—opt for flat bases, high transparency and standard formats (90 mm). Grids make counting easier; avoid scratches and bubbles in the agar.