Petri Dishes, Clear Glass

Quick Answer: Petri Dishes, Clear Glass are round, shallow glass dishes with a loose-fitting cover, used in school and college biology for observing specimens, germinating seeds and holding culture media. Clear glass petri dishes are normally made of soda-lime glass rather than borosilicate, which suits unheated and moderate-temperature work.

What Clear Glass Petri Dishes Are Used For

In a school biology lab a petri dish is as much an observation tray as a culture vessel. The clear glass petri dishes in this listing give an unobstructed view from above and below, so pupils can watch cress or mustard seeds germinate on damp cotton wool, follow small aquatic organisms, or examine leaves and flowers under a hand lens without lifting them. The cover keeps specimens moist and free of dust between lessons.

In glassware listings, ‘clear glass’ usually signals soda-lime glass, the everyday glass of bottles and windows. It is transparent and hard-wearing in normal handling but expands more on heating than borosilicate, so it is more likely to crack when moved suddenly from hot to cold. That makes these dishes a sensible choice for observation, germination, staining trays and room-temperature experiments, while plates that are heat-sterilised every week are better made of Petri Dishes, Borosilicate Glass.

Agar can still be poured into soda-lime dishes with some care: warm the dishes first, avoid setting hot glass on a cold or wet bench, and let autoclaved loads cool slowly in the chamber. The dish diameter is not stated in the title, so the size required should be settled before ordering.

Classroom and Lab Uses

• Germinating seeds on moist cotton or filter paper to show the stages of germination
• Demonstrating osmosis with potato strips or raisins in salt water and plain water
• Holding stained onion peel or leaf sections before they are mounted on slides
• Observing bread mould or fungal growth on food samples in a closed dish
• Catching and watching small pond organisms such as daphnia with a magnifier

Care and Handling of Soda-Lime Glass Dishes

• Avoid rapid temperature changes: do not pour boiling liquid into a cold dish or rinse a hot dish under cold water
• Wash in warm water with a mild detergent, rinse, and dry upside down on a plastic draining rack
• In schools, tape the lid to the base after inoculation and dispose of grown plates by autoclaving, never by opening them
• Store bases and lids nested in stacks so rims are not chipped

Specifications

Why Choose LabEquip

School science departments and teacher-training colleges usually buy clear glass dishes by the dozen for germination and observation practicals, where heat shock is rarely an issue. LabEquip lists them with the wider Biology Lab Products range, and class-set quantities can be requested through our contact page.

Frequently Asked Questions

What is the difference between clear glass and borosilicate petri dishes?

Clear glass dishes are normally soda-lime glass, which is transparent and robust in everyday handling but cracks more easily with sudden heating or cooling. Borosilicate dishes tolerate repeated autoclaving and oven sterilisation, so they are preferred for regular microbiology work.

Can clear glass petri dishes be autoclaved?

Soda-lime glass can go through an autoclave cycle if it is heated and cooled gradually, but it is more prone to cracking than borosilicate. For plates sterilised every week, borosilicate or pre-sterile plastic dishes are the safer choice.

Are these dishes suitable for growing bacteria in a school?

They can hold agar, but school culture work should follow safe practice: use only approved non-pathogenic organisms, tape the lid shut after inoculation, incubate at no more than about 30 °C, and never open plates once growth has appeared.

How do I set up a seed germination experiment in a petri dish?

Line the base with two layers of filter paper or cotton wool, wet it without leaving standing water, and space the seeds evenly. Replace the lid to hold humidity, keep the dish in light or dark as the experiment requires, and add water daily so the paper never dries.

Why does condensation form under the lid?

Moisture from the contents evaporates and condenses on the cooler lid. A light mist is normal; heavy droplets mean the dish is too wet or too warm, so reduce the water or move the dish out of direct sunlight.

How should broken glass dishes be disposed of?

Collect the pieces with a brush and dustpan, never by hand, and put them in a rigid container marked for broken glass. If the dish held a culture, disinfect or autoclave the pieces first.

Last Updated: September 2026