MicroLab229 UTK Fall 2025 Final

What does GYE plus cycloheximide test for?

actinomycetes and bacteria

What does Violet red bile glucose agar test for

Selective for gram negative. Red/purple colonies w/ red/purp halo: Glucose fermentation

What does the media m-Endo test for?

Gram negative. Red colony: lactose fermentation + metallic sheen colony: E. coli

In the chicken skin experiemnt, what media was used to test for heteotrophic bacteria

SMA (nonselective nondifferential)

What does SDA test for in the soil experiement

Selective for fungi (acidic)

What does blood agar (TSA 5% sheep blood) test for

Nonselective and differential (Hemolysis). Beta hemolytic is yellow zone of clearing

What does wilkins chalgren agar test for

Cultivates anaerobes. Non selective. Has vitamins essential for anaerobic

What does pseudocel agar test for

Selective for Pseudomonas aerunginosa. Positive test is green

What does mitis salivarius agar select for? Describe the shapes of the bacteria when they are present

Differential for: Streptococcus mitis, S. salivarius, enterococci
Selects against gram negative and most gram positive
Enterococcus: Dark blue circle
Strep mutans: Spit with blueish middle
Strep mitis: Lighter blue circle than entero
Strep sali: Looks like spit

Fill in this graph

Hemolytic pathogens, Gram + vs Gram -, Halophiles, Yeasts, Pseudomonas aerunginosa, Relevant anaerobic bacteria, Strep mitis, S. Salivarius, enterococci, Streptococci

Describe the structure of virus

Head (contains DNA), Tail, Tail fibers

Difference in antibody and antigen

Antibody → the protein your immune system makes in response to a pathogen
Antigen → Part of pathogen your immune cell recongizes

Describe structure of antibody

Fc region. Antigen binding site. Antigen

What is the function of an ELISA? List the steps for an ELISA

Detects antibodies in sample. Coat wells with antigen. Add blocking agent. Add antibody. Wash to remove any unsecure antibodies. Add secondary then wash. Add substrate to see color change.

What does an EMB agar test for?

Likes gram negative rods. May or may not ferment lactose. Purple/black colonies = Lactose fermentation

Lytic phase versus Lysogenic phase

Lytic: Viral genes are transcribed and translated by host.
Lysogenic: Virus genome is inserted into host genome

Name the steps of the Lytic cycle

Absorption, Penetration, Synthesis, Maturation, Release

Name the steps of Lysogenic cycle

Absorption, Penetration, Integration, division, induction

What does a PCR do? What is the process?

Increase number of copies of 16S rRNA genes. Denature (95 degrees) Anneal (55 degrees) Extend (72 degrees)

Good primer sets have the same properties of what? If there is high GC content, what happens?

Tm within 5 degrees. Tm between 60-70 degrees. Higher GC = Higher Tm

Write equation for TM

=64.9+((41(# of G’s and C’s - 16.4)/Total letters in read))

What is the purpose of ethidium bromide in the gel?

Make DNA fluoresce!

When you read a sanger sequence from the bottom up, what is that called? If you complemnet that, what is that called?

Sanger result/Synthesized reverse complement. Dna template sequence

What is query coverage?

Percent of your sequence that aligned to genbank (closer to 100% the better)

What is E-value?

Number of matches one can expect from random chance when searching database (closer to 0 the better)

What is percent identity

Extent to which the database and query sequence have the same bases in the same position (closer to 100% the better)