Petri Dishes, Borosilicate Glass

Quick Answer: Petri Dishes, Borosilicate Glass are shallow, flat-bottomed round dishes with a loose-fitting lid, made from low-expansion borosilicate glass. Microbiology and biology labs use these borosilicate glass petri dishes to pour agar plates and grow bacterial and fungal cultures, then wash and heat-sterilise them for reuse.

Why Borosilicate Suits Reusable Culture Dishes

Each petri dish is a pair: a base and a slightly wider lid that rests over it, leaving a narrow gap through which air can pass while settling dust and mould spores are kept off the agar. In this listing both parts are made of borosilicate, the same glass family used for beakers and flasks. Its low coefficient of thermal expansion is the reason borosilicate laboratory glassware copes with hot-air oven sterilisation and steam autoclaving cycle after cycle, with far less risk of cracking than ordinary soda-lime glass.

Reusable glass plates make most sense where sterilising is done in-house: college microbiology practicals, teaching labs that repeat the same streak-plate and pour-plate exercises every term, and departments trying to cut single-use plastic. Glass also shrugs off alcohols and acetone that craze polystyrene, so the same dishes can soak small metal parts in solvent or act as shallow evaporating dishes for crystallisation work.

Compared with the clear glass version in the same range, borosilicate glass petri dishes are the ones to pick when plates will be heat-sterilised week after week; the clear glass dish suits observation and unheated work. Diameters of 90 mm and 100 mm are the most common for culture work, but the size of this listing is not given in its title.

Applications of Borosilicate Glass Petri Dishes

• Pouring nutrient agar plates for streak-plate isolation and colony counts in microbiology practicals
• Testing antibiotic discs or plant extracts for zones of inhibition on seeded agar
• Germinating seeds on moist filter paper to compare the effect of light, water or salt
• Holding leaves, pollen or pond water for examination under a hand lens
• Small-scale evaporation and crystallisation of salt solutions in chemistry

Specifications

Cleaning and Sterilising Glass Petri Dishes

• Autoclave used culture plates before washing, so organisms are killed before the agar is scraped out
• Soak in warm detergent solution, scrub lightly, rinse, and finish with distilled water to avoid spotting
• For dry-heat sterilisation, wrap stacks in paper or load them into a metal petri dish canister and start from a cold oven
• Inspect rims for chips before use; a chipped lid lets contaminants in and can cut fingers

Why Choose LabEquip

Microbiology teachers, college practical in-charges and hospital training labs order these dishes in class-sized sets so that plates can be sterilised and reused through the year. As a laboratory petri dish supplier, LabEquip can pack them together with other items from the Biology Lab Products range for a new lab; send sizes and numbers through the contact page.

Frequently Asked Questions

How is borosilicate glass different from clear glass for petri dishes?

Borosilicate glass expands very little when heated, so it tolerates repeated autoclaving, hot-air oven sterilisation and hot agar with less risk of cracking. Clear glass dishes are usually soda-lime glass, which is more sensitive to sudden temperature changes and better kept for unheated work.

Can borosilicate petri dishes be autoclaved?

Yes, borosilicate glass generally withstands steam autoclaving at 121 °C. Keep lids on the bases, place the dishes in a tray or canister, and let them cool slowly inside the autoclave before handling.

What temperature is used for dry-heat sterilisation of glass petri dishes?

A hot-air oven cycle of about 160 °C for two hours, or 170 °C for one hour, is widely used for glassware. Load the dishes into a cold oven and let them cool before opening the door, so the glass is not shocked.

Why are culture plates incubated upside down?

With the agar side uppermost, condensation from the lid cannot drip onto the agar surface and run colonies together. Inverting the plate also slows drying of the agar during longer incubations.

How much agar should be poured into each dish?

For a standard 90 mm dish, about 15 to 20 ml of molten agar gives a layer deep enough for streaking and disc tests. Pour at around 45 to 50 °C and let the plates set on a level bench with the lids on.

Are glass petri dishes better than disposable plastic ones?

Glass dishes are reusable and heat-sterilisable, which suits teaching labs that sterilise in-house and want less plastic waste. Pre-sterile plastic dishes save washing time and remove breakage risk, so many labs keep glass for routine practicals and plastic for large one-off runs.

Last Updated: September 2026