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5 Important Microbiology Lab Techniques Your Students Should Know

Ginelle Testa
Teaching with Labster
Microbiology

If you’re teaching a course in microbiology, perhaps you’re looking for resources to help you introduce or reinforce fundamental microbiology lab techniques that every student should know.

There are many lab techniques to examine and characterize microbes, but we’ve identified five basic ones (thanks to Clinical Gate!) that start with the letter “I” to make them easier to remember. 

The five I’s of microbiology lab techniques: 

  • Inspection

  • Identification

  • Inoculation

  • Incubation 

  • Isolation[1]

We’ve also identified 5 Labster virtual labs that help you teach each technique. Not only can your students learn the methods, but they can also have fun along the way!

1. Inspection

Inspection is also known as observation, where you look at the microorganism through a microscope, as microorganisms are too small to be seen with the unaided eye.

Our virtual lab that teaches inspection is:

Microscopy

Join the Microscopy lab and learn about the different types of microscopy to understand the mechanisms behind it. You will be trained in light microscopy, transmission electron microscopy, and fluorescence microscopy.

You will learn about fluorescence staining techniques and how they can be used to visualize specific structures. For example, by staining the DNA with DAPI, you can easily identify a cell’s nucleus. In this part of the lab, you will examine a chicken intestine sample that is infected with a retrovirus and observe how the virus infects the lymphocytes and how it inhibits inflammation. The retrovirus can be further developed as a medicine for coeliac disease.

Microscopy

2. Identification

Identification is the classifying of one microorganism as different than another. [2] There are many ways to identify them, such as their color, shape, size, and smell. 

Our virtual lab that teaches identification is: 

Identification of Unknown Bacteria: Help save baby Kuppelfangs from an epidemic! 

Visit the imaginary exoplanet Astakos IV, where the Kuppelfang population is suffering from a bacterial infection. Use staining, differential media, and biochemical tests to identify the bacteria so that the Kuppelfangs can be treated before they go extinct.

In this simulation, you will learn to identify unknown bacteria. Just like in clinical settings on Earth, it is important to identify unknown pathogens for diagnosis and treatment. Explore clinical microbiology techniques, such as differential staining, differential and selective media and biochemical assays, then use your new skills to identify the bacteria.

Identification

3. Inoculation

Inoculation is introducing microorganisms, such as bacteria, in a culture medium. [3] Vaccines are also known as inoculation, as they introduce antigens into the body to stimulate a response from the immune system. 

Our virtual lab that teaches inoculation is: 

Biosafety

In the Biosafety simulation, you will be introduced to the concept of laboratory containment, which is a very special type of laboratory required to work with hazardous pathogens. You will become familiar with the basic protocols utilized to ensure safety, and you will be presented with the specific basic safety rules for this type of laboratory (e.g. personal protective equipment (PPE) and primary containment). In addition, you will learn how every part of the laboratory is designed to avoid contamination. This includes learning about why the pressure in the laboratory needs to be controlled at all times (secondary containment), and how the microbiological safety cabinets are designed to offer protection.

In the Biosafety simulation, you will be presented with a hypothetical case where you will need to identify a potential bioterrorism agent that is classed as a hazard group three microorganism.

Innoculation

4. Incubation

Incubation is an essential microbiology lab technique. It often takes days or weeks, but one of the great things about microbiology virtual labs is you don’t have to wait that length of time! It can be instant so that students can learn right away.

Our virtual lab that teaches incubation is: 

Bacterial Quantification by Culture

Your colleague has just returned from an expedition to the Amazon rainforest, and has brought back a promising sample; a fungus that seems to inhibit bacterial growth. Your mission is to quantify the effect of this antibiotic compound on bacterial growth. But, you will only be able to succeed if you manage to combine smart experimental design, some simple mathematics, and proper microbial culture techniques.

In a real lab, this experiment would take a week or more to complete, but in this simulation, it only takes 30 minutes! 

Last, you will incubate the bacterial culture with the antibiotic compound to quantify the effect of the compound on bacterial growth.

Will you be able to determine if the fungal compound can be used as a new antibiotic?

Bacterial Quantification by Culture

5. Isolation

There are many ways to separate strains to be isolated from each other. There are two main ways to isolate bacteria: streaking on an agar plate and the pour plate method. [4]

Our virtual lab that teaches isolation is: 

Bacterial Isolation

In the Bacterial Isolation simulation, you will investigate the cause of contamination of poultry meat by a dangerous bacteria strain that is resistant to common antibiotics. After taking samples from the chicken farm, you will work in the virtual laboratory to isolate single colonies of the deadly bacteria among a variety of different species. To do so, you will learn how to work under sterile conditions, and you will be able to practice and perfect your plate streaking technique.

bacterial isolation

Wrap-up of techniques

In summary, here are the 5 microbiology lab techniques and their accompanying virtual labs:

  1. Inspection: Microscopy

  2. Identification: Identification of Unknown Bacteria: Help save baby Kuppelfangs from an epidemic! 

  3. Inoculation: Biosafety

  4. Incubation: Bacterial Quantification by Culture

  5. Isolation: Bacterial Isolation


Each of these labs can help your students better grasp the techniques required in microbiology. 

Questions to think about:

  • How could you incorporate these labs into your teaching plans?

  • Are these labs better as self-paced homework assignments or small-group collaboration in class?

Interested in these labs? Try them for 30 days with our all-access pass to Labster’s full catalog of virtual labs, including these microbiology labs! 

Sources

[1] “Microbiological Laboratory Techniques.” Clinical Gate, 2 Mar. 2015, https://clinicalgate.com/microbiological-laboratory-techniques/#:~:text=Microbiologists%20use%20five%20basic%20procedures,platinum%20wire%20probe%20streaked%20across. 

[2] Classification - Medical Microbiology - NCBI Bookshelf. https://www.ncbi.nlm.nih.gov/books/NBK8406/. 

[3] “Inoculation.” Biology Articles, Tutorials & Dictionary Online, 13 Jan. 2022, https://www.biologyonline.com/dictionary/inoculation. 

[4] “Bacterial Isolation.” Microbiology Resource Center - Truckee Meadows Community College, https://www.tmcc.edu/microbiology-resource-center/lab-protocols/bacterial-isolation#:~:text=There%20are%20two%20main%20ways%20to%20isolate%20organisms.&text=Streaking%20for%20isolation%20on%20an%20agar%20plate%20involves%20the%20successive,rise%20to%20recognizable%20individual%20colonies.