How to Use Petri Dishes effectively in Laboratory

What are Petri dishes?

Petri dish is a shallow cylindrical, round glass that is used in laboratories to culture different microorganisms and cells. To study microorganisms like bacteria & viruses under great observation, it is important to keep them isolated from other species or elements. In other words, Petri dishes are used to support the growth of microorganisms. One of the most effective ways to do this is with the help of the culture medium in an appropriate container. Petri dish is the best choice for a culture medium plate. 

The plate was invented by a German bacteriologist named Julius Richard Petri. Petri dish is not surprisingly, named after him. Since its invention, Petri dishes have become one of the most important laboratory equipment. In this Science Equip article, we’ll find out in detail how to use Petri dishes in as science equipment laboratories & its various purposes.

Uses of Petri dishes in a laboratory

Petri dish is majorly used as laboratory equipment in the field of biology & chemistry. The dish is used to culture cells by providing storage space and preventing them from getting contaminated. Since the dish is transparent, it is easy to observe the growth stages of microorganisms clearly. The size of the Petri dish enables it to be kept under the microscope directly for observation without the need to transfer it onto a microscopic plate. At a basic level, a Petri dish is used in schools and colleges for activities like the observation of seed germination.


How to use Petri dishes effectively in a laboratory

Before using a Petri dish it is important to make sure that it is absolutely clean and free of any microparticles that may affect the experiment. You can ensure this by treating every used dish with bleach and sterilizing it for further use. Make sure you sterilize the Petri dish before using it as well.

To observe the growth of bacteria, begin with filling the dish with agar medium (prepared with the help red algae). Agar medium contains nutrients, blood, salt, indicators, antibiotics, etc. that help in the growth of microorganisms. Proceed by storing the Petri dishes in the refrigerator in an upside-down position. When you need the culture plates, remove them from the refrigerator and use them once they are back at room temperature.

Moving ahead, take a sample of bacteria or any other microorganism and slowly pour it on the culture or use a cotton swab to apply it on the culture in a zigzag manner. Make sure you aren’t applying too much pressure as this may break the culture.

Once this is done, close the Petri dish with a lid and cover it properly. Store under approx 37ºC for a few days and allow it to grow. After a few days, your sample will be ready for further research.


Also read: Benefits of Wearing a Disposable Face Mask to Prevent Coronavirus


We hope this article helps you understand the correct usage of Petri dishes effectively. Reach out to us at Science Equip for more information on laboratory equipment and apparatus.

  • Mar 05, 2020
  • Category: News
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