BIO251 Laboratory Images, Videos, and Study Material

Video of aseptic technique (.mpg file)

Video of how to effectively use your compound light microscope (.mpg file)

Video of smear preparation and simple staining (.mpg file)

The images below are available as a study tool for the laboratory section of the BIO251: Medical and Public Health Microbiology course. 

Microscopic images of various bacteria under various staining techniques and plates we have used. (EXAM 1 prep material)

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Gram stain of Escherichia coli

Gram stain of a Bacillus species

Gram stain of Staphylococcus aureus

An endospore stain of Bacillus cereus using malachite green

Capsule stain of bacilli bacteria

Acid-Fast stain of a Mycobacterium species


Kirby-Bauer disc diffusion test for antibiotic susceptibility



These images are labeled only with the name of the biochemical test and the media that test is being performed in/on.  It is not the goal of this course to have you memorize which species is positive for which biochemical test.  Rather, as you study focus on how a test is performed, what you learn about an organism from that test, and how a positive result is detected using the appropriate media/reagents. (EXAM 2 prep material)

Click on a thumbnail image to view full-size.

Casein hydrolysis demonstrated on a skim milk agar plate


Carbohydrate Fermentation of glucose, lactose, and sucrose


Lysine decarboxylation as demonstrate in an lysine decarboxylase broth



Methyl Red test performed in a glucose-rich MRVP broth


Hydrogen Sulfide, Indole production, motility demonstrated in a SIM tube


Starch Hydrolysis performed on a starch agar plate



Carbohydrate utilization demonstrated on triple sugar iron (TSI) agar slants


Urease activity demonstrated in a urea broth


Voges-Proskauer test performed in a glucose-rich MRVP broth


Citrate utilization demonstrated on a Simmon's citrate slant

Snyder test agar for dental caries

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Phenylalanine Deaminase activity demonstrated on a Phenylalanine agar slant

Beta hemolysis (left) and alpha hemolysis (right) on a blood agar plate

Mannitol salt agar plate demonstrating mannitol fermentation and non-fermentation

A lactose fermenter and a non-lactose fermenter demonstrated on EMB