Petri dish : Definition, Types and Uses

Summary :

◉ What is a Petri dish ?

A Petri dish is a cylindrical lidded dish made of shallow clear glass or plastic, used to hold a thin layer of agar. Used to cultivate bacteria, fungi and other microorganisms.

The Petri dish is named after its inventor, Julius Richard Petri (1852-1921) who worked as an assistant to Robert Koch in Berlin at the Imperial Health Office. He developed a double dish, small, round, flat-bottomed with sides. One of the two dishes was slightly larger, serving as a lid and a shield. Designed with two basic principles:

  • Separation : Cultivating microorganisms while separating them from airborne contaminants, and after culture, separating individuals (handlers) and the environment from these bacteria.
  • Transparency / Visibility : It allowed researchers to easily observe and study microorganisms in a controlled environment.

Petri originally called the dish a "cell culture dish," but it eventually became known as a Petri dish in his honor.

 Petri dish

◉ Petri dish uses

Petri dishes have a wide range of uses, mainly in the laboratory, including :

◉ Types of petri dishes

Petri dishes are available in a variety of shapes, sizes and materials. The choice of petri dish used depends on the specific application and the needs of the laboratory. Here are some common types of petri dishesc:

Size : They come in various sizes, ranging from a few millimeters to several centimeters in diameter:

Shape : Petri dishes are typically circular in shape, but some specialty petri dishes may have other shapes. Researchers choose the shape of the petri dish based on the specific requirements of their experiment :

Material : petri dishes can be made from a variety of materials, including :

Surface : The surface of a petri dish can be smooth or have a textured surface. Textured surfaces can promote the growth of certain microorganisms or help to prevent bacterial swarming.

Lid : Petri dish lids can be solid, vented, or semi-permeable. Vented lids allow for gas exchange and are useful for growing anaerobic microorganisms, while semi-permeable lids can control the humidity level in the dish.

Stacked petri dish : This type of petri dish has multiple compartments that can be stacked on top of each other, allowing for efficient use of space in crowded laboratory environments.

Sections : Some petri dishes have sections or compartments that allow for multiple types of media to be used on a single plate or for testing multiple samples at once.

Coated petri dishes are petri dishes that have been treated with a layer of material (such as collagen, fibronectin, laminin, or extracellular matrix proteins) that is designed to promote cell attachment and growth.

Principe simplifié du filtre seringue

Different types of petri dishes

◉ Features

◉ Frequently Asked Questions

What is in a Petri dish to grow bacteria ?

A Petri dish used for culturing bacteria usually contains agar which provides the nutrients and environment necessary for bacterial growth. Different types of agar with different compositions (beef extract, peptone, salt, etc) are used depending on the bacteria to be searched for.

Can polypropylene Petri Dish be autoclavable ?

Yes, Polypropylene Petri dishes are generally autoclavable. Polypropylene is a type of plastic that is heat-resistant and can withstand high temperatures without melting or deforming. However, it is important to check the manufacturer's instructions

Can I use petri dish for cell culture ?

Yes, they are commonly used for cell culture in research and clinical laboratories. However, it is important to choose the right type of petri dish and ensure that it is sterile before use.

Can plastic petri dish be autoclaved?

Disposable plastic petri dishes cannot be sterilized in an autoclave as they will melt.

Petri dish, a petri plate or cell-culture dish, are commonly used to refer to the same item : a shallow cylindrical containers with fitted lids.