If you operate a microbiology lab, a pharmaceutical QC suite, or a teaching prep room where extensive washing, sterilization, and plating are routine, you have probably wondered about the benefits of glass Petri dishes compared to the plastic alternatives. In a lot of situations, especially where optical clarity is required and plastic dishes are guaranteed to haze, the ability to withstand heat for repeated autoclaving, and the overall cost of ownership throughout the life of glass Petri dishes are greater than that of single-use plastic dishes, glass dishes are worth the cost.

This article provides a no-frills overview of glass Petri dishes, including the materials used, the process of sterilization and usage, available sizes and customizable options, and selecting the best one for your laboratory workflow. We will also highlight the advantages of borosilicate glass and how a good supplier can help with global standardization for disparate teams, SOPs, and processes.

What is a glass petri dish and when should you choose it?

A glass petri dish is a shallow, lidded, and cylindrical dish that is used for the culture and observation of microbes, small organisms, or cell colonies on solid or semi-solid nutrient agar and other culture media. The ability of the dish for excellent optical clarity and dimensional stability is the reason it is a standard tool in classic microbiology workflows, especially heat sterilization, antibiotic susceptibility testing, surface sampling, air-settle plates colony isolation, and isolation training.

When You'll Want Glass and Not Plastic

When your priority is reusability (wash, dry, and autoclave), and the reduction of costs and waste for every run, glass is your best bet.

When you need unhindered vision for real-time big scratch-resistant viewing for photographs and for assessing the morphology of your colony.

When you run high temperature procedures such as dry-heat oven conditioning and prefer to have low thermal expansion.

When you prefer chemical resistance to the common cleaning agents and solvents used in the care of lab glassware.

In training labs and academic courses, using glass also aids students in learning proper aseptic technique, as glassware is consistent in its behavior post sterilization cycles—it won’t warp, the lids won’t drift and fit, and it won’t fog or surprise with changes.

Why a borosilicate glass petri dish is the benchmark

Most premium quality glass Petri dishes use borosilicate glass (often called Boro 3.3, Type I, Class A). This specific glass is ideal as it provides:

High thermal shock resistance, stability to low expansion glass and autoclave cycles, and dry-heat conditioning.

Chemical durability and resistance to common detergents, lab reagents, alcohols, and glass.

Optical quality glass as it provides high optical clarity and minimal visual artifacts when inspecting zones of inhibition, countable plates, or colonies.

Standards to know when evaluating material claims:

ASTM E438 lists the different types of lab glass and states that Type I borosilicate glass should be used for lab apparatuses due to its chemical durability and thermal resistance.

ISO 13132:2023 offers specifications and test requirements for laboratory glassware—specifically Petri dishes—focusing on performance and dimensional uniformity.

When vendors write “Type I, Class A” or “Boro 3.3” on their spec sheets, they indicate adherence to the glass standards that your QA team will be satisfied with for the writing or the auditing of the SOP.