Petri Dishes Disposable – Gamma Sterile

Quick Answer: Gamma sterile Petri dishes are disposable plastic culture dishes sterilised by gamma irradiation after packing, so they arrive sterile and ready for pouring agar. They suit microbiology work where plates must be free of contaminants and plastic dishes cannot be heat-sterilised.

What Gamma Sterilisation Means for the User

Polystyrene dishes cannot be autoclaved, so manufacturers sterilise them another way. In gamma sterilisation, sealed packs of dishes are exposed to gamma rays, usually from a cobalt-60 source, which kill microorganisms throughout the pack without heat. The dishes do not become radioactive and can be used as soon as the sleeve is opened.

Sterility lasts only while the pack stays sealed and intact. Before use, look for tears in the sleeve and any expiry date printed on it, open it in a clean area such as a laminar flow cabinet or beside a Bunsen flame, and take out only the dishes needed. Fold and tape the sleeve shut to protect the rest.

Compared with non-sterile disposable Petri dishes, gamma sterile plates remove the doubt about whether contamination came from the dish itself. That matters when teaching aseptic technique and when testing environmental, water or food samples, where a stray colony changes the result.

Specifications

Care & Handling

• Inspect every sleeve for tears or broken seals; dishes from damaged packs are not used for sterile work.
• Open sleeves in a biosafety cabinet or near a Bunsen flame and lift dishes by their edges.
• Reseal part-used sleeves with tape and write the opening date on them.
• Store unopened sleeves flat, dry and out of sunlight.

Applications

• Pouring selective and general media for microbiology practicals
• Settle plates for environmental monitoring in clean rooms or hospital training labs
• Water and food sample counts where the dish must be ruled out as a contamination source
• Teaching aseptic technique with a clean starting point for every student

Why Choose LabEquip

Microbiology labs, hospital training units and food-testing courses choose gamma sterile plates to save autoclave time and to be sure the dish is not the source of contamination. LabEquip lists them in the Biology Lab Products range; send media volumes and plate counts through the contact page.

Frequently Asked Questions

Does gamma sterilisation make the Petri dishes radioactive?

No. Gamma rays pass through the dishes and kill microorganisms but leave no radioactivity in the plastic. The dishes are safe to handle and use straight away.

How long do gamma sterile dishes stay sterile?

They remain sterile while the sealed sleeve is intact. Once a sleeve is opened, the remaining dishes are exposed to room air, so reseal it, use the rest soon and keep doubtful ones for less demanding work. Follow any expiry date on the pack.

Why not simply autoclave plastic Petri dishes?

Polystyrene, the usual material, softens and deforms at autoclave temperatures. Gamma irradiation sterilises the dishes without heat, so they keep their shape and clarity.

Do I still need aseptic technique with sterile dishes?

Yes. The dish is sterile, but air, hands, media and the work surface are not. Lift the lid only as far as needed, work near a flame or in a cabinet and keep the plate covered as much as possible.

What is the difference between gamma sterile and EO sterile dishes?

Both are sterile. Ethylene oxide sterilisation uses a gas that must be aired out of the packs afterwards, while gamma irradiation leaves no residue. For routine microbiology either is suitable when the packing is intact.

Can gamma sterile dishes be used for cell culture?

Standard Petri dishes are not surface-treated for animal cell attachment, so adherent cells may spread poorly on them. For mammalian cells, use dishes, flasks or plates labelled as tissue-culture treated.

Last Updated: September 2026