Standard Glass Petri Dishes with Covers

The Petri dish — devised by Julius Petri in Robert Koch's lab in 1887 — is the shallow round dish used to grow micro-organisms on a layer of agar. Its loose, overlapping lid is deliberate: it keeps airborne contaminants out while allowing a little gas exchange, so cultures can breathe without being exposed.

Glass Petri dishes are reusable and autoclavable, so labs that culture heavily and want to avoid single-use plastic favour them; the high clarity of borosilicate makes colonies and growth easy to examine.

Microbial culture on agar, colony counting and isolation, cell and tissue work, spore germination and plant tissue culture, and sample drying or evaporation, in microbiology teaching, QC, environmental monitoring and research labs.

A shallow borosilicate 3.3 base with a loose overlapping lid that vents through the overlap. High-clarity glass aids examination and colony counting. The dishes are autoclavable and dry-heat sterilisable for reuse, and bases and lids are paired by size.

Sterilise by autoclave or dry heat before use; pour agar, let it set, and incubate inverted to stop condensation dripping onto the culture. The loose lid must stay loose to allow gas exchange — do not seal it. Handle aseptically, and dispose of or decontaminate cultured dishes safely before washing for reuse.

Pressed or formed from borosilicate 3.3 into the shallow base and lid, then annealed for autoclave durability. Flatness (so the agar sits evenly), clarity and the lid-to-base overlap fit are the key checks for reliable culturing.