Microbiology Lab Practical Flashcards
What is Body Temp?
37° F
What is Room Temp?
25°F
What is a broth?
a fluid medium for bacterial growth
What is an agar?
a solid gel-like form in a plate for bacteria to grow on
What is an agar deep?
a solid agar material in a tube
no slant
What is an agar slant?
a solid agar material in a tube made at a slant in a tube
What is aseptic technique?
aseptically transfer bacteria from one source to another without breaking sterility
What is a gram stain?
a series of stains that has a specific order and has specific amounts of time for each stain
What stains do you use in a gram stain?
- Crystal Violet
- Grams Iodine
- Acetone
- Safranin Red
What does a gram stain tell you?
- morphology
- G +/-
- arrangement
What is a negative stain?
- use India ink
- only stain you don’t heat fix
What does a negative stain tell you?
morphology only
What stains are used in an endospore stain?
- Malachite Green
- Alcohol
- Safranin Red
What does an endospore stain tell you?
helps determine whether bacteria is a spore-forming bacteria or not
What type of bacteria G +/- are endospores usually?
G (+) rod
What is a capsule stain used for?
can see if the bacteria has a capsule or not
What stain do you use in a capsule stain?
India ink
What is a counterstain?
a stain meant to help make something else stand out better
What does gram variable mean?
- both G(+) and G(-)
- pink G(-)
- blue G(+)
What is an acid fast stain used for?
good for bacteria that has a lipid (fatty) cell wall which can be difficult to stain
What is selective media?
allows growth of specific organism
What are differential media?
used to distinguish one organism from another
What is a lawn of bacteria?
creating a solid sheet of bacteria on a plate
What does bacteriostatic mean?
- stops the growth of bacteria
- doesn’t kill bacteria
Where is the bacteriostatic range on a plate with antibiotics?
the edge of the circle where an antibiotic has killed bacteria
What does bactericidal mean?
kills bacteria
Where is the bactericidal range on a plate with antibiotics?
ring around the antibiotics where there is no bacterial growth
How can you measure the bactericidal range?
- with a ruler
- in mm
What is serial dilution used for?
to dilute one ml of a sample to grow countable number of colonies
What is a vegetative cell?
an inactive cell
What is an endospore?
a vegetative cell that can form a spore
What is an obligate aerobe?
needs oxygen to survive
What is an obligate anaerobe?
can’t survive in oxygen
What is a facultative anaerobe?
- can live with or without oxygen
- prefers oxygen
What is a bacterial capsule?
a thick glycocalyx shell around a bacteria
What does an alpha hemolysis do?
- partial hemolysis
- hazy halo around growth
What does a beta hemolysis do?
- complete hemolysis
- clear halo around growth
What does a gamma hemolysis do?
- no hemolysis
- grows on top of agar
What is a catalase test used for?
Designed to detect bacterial respiration producing the “catalase” enzyme
What does a positive catalase test look like?
will have bubbles
What is an oxidase test used for?
Designed to detect bacterial respiration producing the enzyme “cytochrome oxidase”
What does a positive oxidase test look like?
will turn purple
What is a bromcrestol slant used for?
Determines if bacteria can utilize glucose for nutrient growth
What does a positive bromcrestol slant look like?
will turn yellow
What are phenyl red glucose, sucrose, and lactose tests used for?
- Determine if bacteria can utilize the carbohydrate glucose, lactose, or sucrose
- Has a “durham” tube to show whether or not bacteria is growing because gas will be produced
What does a positive phenyl red glucose, sucrose, and lactose test look like?
- will turn yellow from red
- durham tube will have a gas bubble if bacterial growth
What is a simmons citrate agar used for?
Determines if the bacteria can utilize sodium citrate (carbon) as a source for survival
What does a positive simmons citrate test look like?
will turn brilliant blue
What is a urea agar test used for?
Determines if bacteria contains an enzyme called “urease”
What does a positive urea agar test look like?
color will change to a brilliant pink
What is a MRVP broth made up of?
- MR: methyl red
2. VP: voges proskauer
What is a Methyl Red (MR) used for?
Reagent designed to detect organisms that can overcome a phosphate buffer and can lower the pH of an environment
What does a positive Methyl Red (MR) test look like?
turns very red
What is a voges proskauer test used for?
Reagent designed to detect bacterial fermentation that produces “acetoin”
What does a positive voges proskauer test look like?
will have a really dark ring of red-brown at the top of the tube
What does a sims tube test used for?
Provides ability to determine 3 characteristics of a single bacteria
What does a positive sims test look like?
Indole: red section at top of tube
Motility: cloudy agar
Sulfur: black
What is a TSA plate used for?
everything, anything
What is a glucose min. salt plate used for?
salt and sugar loving bacteria
What does a glucose min. salt plate promote?
G(-)
What does an EMB plate promote?
G(-)
What does an EMB plate inhibit?
G(+)
What does a PEA plate inhibit?
G(-)
What does a PEA plate promote?
G(+)
What does an Endo plate promote?
G(-)
What does an Endo plate inhibit?
G(+)
What is a mannitol salt plate used for?
salt loving bacteria
What does a MacConkey plate inhibit?
G(+)
What does a MacConkey plate promote?
G(-)
What plates have lactose?
- EMB
- Endo
- MacConkey
What plates can grow/show coliforms?
- EMB
- Endo
- MacConkey
Does E. coli and/or S. aureus grow in a 2% salt solution?
both
Does E. coli and/or S. aureus grow in a 5% salt solution?
S. aureus
Does E. coli and/or S. aureus grow in a 8% salt solution?
S. aureus
Does E. coli and/or S. aureus grow in a 11% salt solution?
S. aureus
