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186 Cards in this Set
- Front
- Back
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_____________ microscopy is used when viewing dead or stained material |
Bright field |
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_____________ is used when viewing live or unstained material |
Phase-contrast |
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When you first come into the lab and before you leave, what two things should you always do? |
Wash your hands and clean the counter |
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Which staining method is used to determine the thickness of the peptidoglycan layer? |
Gram stain |
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Where should you dispose slides |
Side trays at end of bench |
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Where should you dispose of used Pipettes |
Nalgene bucket |
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Where do used test tubes go |
Trash cart |
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Where does contaminated glass go |
Slide tray at end of bench |
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Where does uncontaminated glass go |
TA will clean it up and out it in the broken glass container at front of class |
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What are the three main factors to obtaining a good image in microscopy? |
Contrast, magnification, resolution |
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What two items are used to clean the microscope lenses? |
Lens paper and lens cleaner |
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Which objective lenses can be used with immersion oil |
100x |
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Why do gram-negative organisms lose the primary stain during decolorization? |
They have thinner cell walls (peptidoglycan layer) so the color does not stay. |
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What is the purpose of a mordant in staining? |
Make sure the color stays |
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Which staining procedure provides the quickest means of determining the morphology of an organism? |
Simple stain |
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Which dues are used for acid-fast stain? |
Carbol fuchsia and methylene blue |
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What is the spherical shaped bacterial morphology called |
Cocci |
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Give an example of a gram positive bacterial species that we used in the gram stain |
Bacillus megaterium |
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How should you store a plate? |
Agar side up |
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What is a control organism |
An organism with a known reaction |
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What is an exospore |
An exospore is a spore outside of the cell that is usually produced by growth or budding |
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Why is the technique of steaming used in the acid-fast and endospore stains? |
To force the color into heat-resistant cells. |
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acid-fast staining is used to identify organisms with a waxy substance called ____________ |
mycolic acid |
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what is the purpose of re-streaking your EI? |
So it doesn't die and stays fresh |
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True or False? The storage conditions test is used to determine what conditions your EI grows best in |
false |
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What is a direct method for enumerating bacteria? |
coulter counting |
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What is an indirect method method for enumerating bacteria? |
spectrophotmetry |
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Why are serial dilutions necessary for viable count assay? |
To lower the concentration. If the concentration is too high, colonies may overlap and it becomes impossible to get an accurate count. |
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Name three possible sources of contamination in hamburger meat. |
storage, processing, packaging. |
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When using colony counting, a plate with over 300 colonies is recorded as _______ When using colony counting, a plate with fewer than 30 colonies is recorded as_________ |
TNTC, NSS |
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If you counted 229 colonies on a plate diluted 10^-5, this is equivalent to _______________ cfu/g |
2.29x10^7 |
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If you are doing a variable assay for enumerating bacteria, and you do 10^-3, 10^-4, and 10^-5 serial dilutions, and get colony counts of TNTC, 150, and 96 respectively, what is your titer? |
5.6x10^6 |
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True or False? A viable count assay is an example of a direct counting method for enumerating bacteria. |
true |
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If you counted 151 colonies on a plate diluted 10^-5, this is equivalent to _______ |
1.51x10^7 |
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Why do we stop counting after 300 colonies? |
It is likely that with a colony count that high, some of the colonies have overlapped, making it impossible to get an accurate number. |
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What does the formation of a dark percipitate in the Kliger's test mean? |
H2S Production |
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A positive result for casein hydrolysis is indicated by the formation of a _______ |
Clear zone |
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in the carbohydrate fermentation test, if gas appears in the Durham tube and color change is observed, how is the test read? |
Positive for acid and gas |
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True or false? Observations of colony morphology, cell morphology, and Gram stain reaction will provide enough data to identify the genus and species of your EI. |
False |
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What does the acronym PCR stand for? |
Polymerase chain reaction |
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What is the purpose of PCR? |
To make many copies of a DNA strand, so it can be identified. |
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If a PCR is run for 10 cycles on one fragment of source DNA, how many copies will there be afterwards? |
2^10= 1024 |
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What does the PCR do? |
Amplifies a strand of DNA so we can sequence it. |
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What are the three stages that need to occur for a successful PCR reaction? |
1. Denaturation 2. Annealing 3. Extension |
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True or False? A gel electrophoresis is used to visualize the general length of product amplified from your PCR. |
True |
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Name the phage and bacteria that were used in the Bacteriophage experiment. |
Phage: T4 Bacteria: E Coli strain B |
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adsorption |
Attachment of the phage to the outside of the host cell. |
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replication |
host cell machinery produces the phage DNA. |
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assembly |
host cell produces capsid, tail and proteins into complete, mature phages. |
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lysis |
Cell bursts |
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burst size |
the amount of viruses in a sample based on the number of cells that burst |
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label a bacteriophage |
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How do plaques help us determine the titer of bacteriophage in a sample? |
It shows us where the cells were that lysed, which helps us to know how many cells were infected because the plaques are like colonies. |
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What will happen to the number of bacteriophage present in a sample once all of the E. coli have been lysed? |
They will decrease because the phage cannot survive without host cell machinery. |
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There are two broad classes of stains: a _______ stain uses only one dye, while a ________ stain uses two or more dyes. |
simple; differential |
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How would you know if broth from your sterile technique quiz became contaminated? |
If it becomes cloudy/turbid |
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If you counted 229 colonies on a plate diluted 10^-5, this is equivalent to ________ |
2.29x10^7 |
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When phenol red turns yellow, what does this indicate about the result of the carbohydrate fermentation test? |
positive |
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In the gelatinase test, what should happen to the negative control when the liquefied substrate is placed at 4 degrees Celsius? |
It will solidify |
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Transformation |
uptake of naked DNA from the environment |
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Transduction |
phage transfer of non-phage DNA |
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conjugation |
Cell to cell transfer with pilli |
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Transfection |
Naked bacteriophage DNA uptake. |
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What is the definition of competence as it relates to bacterial transformation? |
The ability to uptake DNA from the environment. |
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True or False? E. coli is a naturally competent bacteria. |
False |
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Define SD5 AND SD6: __________ is a tryotophan auxotroph (mutant) __________ is tryptophan prototroph (wild-type) |
SD6; SD5 |
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Explain why tryptophan is a necessary molecule for life |
tryptophan is essential in protein synthesis |
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After spreading the SD6 culture over the transformation plate, why would you not expect growth of SD6 cells all through out the plate? |
They do not have tryptophan, and first need to get DNA from the wild type. |
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What would it mean if you found growth within the circles on your control plate? |
That your experiment is invalid. All SD5 cells should have been lysed. |
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Give an example of a benefit a plasmid impart upon a bacterial cell. |
Resistance to antibiotics |
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What is the difference between a chromosome and a plasmid? |
A chromosome contains genetic information that is essential to life, whereas a plasmid contains genetic information that is not essential to life but that benefits the bacterial cell. |
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true or false? a species that is not naturally competent cannot have its genome altered. |
false. |
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The ________ are spherical or oval shaped bacteria. |
cocci |
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Basedon the cell wall composition, what does the Gram stain differentiate?
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The thicknessof the peptidoglycan layer
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This outer covering, makes an organism acid-fast |
mycolic acid |
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Thegenus Mycobacterium isdistinguished with this stain
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Acid-fast |
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oil should only be used on this lens |
100x |
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Phasecontrast is often used with this type of organism.
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live, unstained organisms |
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Underwhichtype of microscopy is stained material commonly viewed?
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Bright-field |
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Whichcomes first:
RisePlateauAssembly |
Assembly, rise, plateau |
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Calculatethe titer for 75 colonieson the10-6 dilution plate
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7.5x10^7 |
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The controlplateinthe transformation exercise was made for this reason.
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tomake sure that all SD5 were lysed
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Whatis the difference between indirect and direct methods of counting
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With direct counting, you are actually counting the colonies. |
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Indicates a (-) reaction for what test? |
motility |
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indicates a (+) test for what? |
Urea Hydrolysis |
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Indicates a (+) reaction for what test? |
Simmons Citrate |
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What is this plate testing for? |
starch hydrolysis |
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Name these oxygen requirements |
A)Obligate aerobe
B)Obligate anaerobe C)Facultative anaerobe D)Microaerophile E)Aerotolerant |
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Whatis the difference between simple and differential staining?
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Simple staining uses only one dye, whereas differential uses more than one and uses control organisms. |
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Whyare endospores formed?
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The cell is in a hostile development so it forms an endospore to help it survive |
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Namethe 3 stains used in the Gram stain?
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Crystal violet, Gram's iodine, and safranin |
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Howmany base pairs were we looking for in our PCR
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290 |
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Be able to label a microscope |
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What organism and stain was used in the simple stain? |
Bacillus megaterium, methylene blue |
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What was the gram-negative organism used in the gram stain? |
Escherichia coli |
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What were the gram-positive organisms used in the gram stain? |
Bacillus megaterium, Staphylococcus epidermidis |
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What was the primary stain and counter stain used in the gram stain? |
Primary: crystal violet counter: safranin |
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What organism was used in the capsule stain? |
Klebsiella pneumoniæ
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What was the primary stain and counter stain used in the capsule stain? |
primary: Congo red counter: Maneval's stain |
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What is a capsule |
apronounced gelatinous, slimy layer called a capsule.
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What organisms were used in the acid-fast stain? |
Mycobacterium smegmatis(+)Bacillus megaterium (-)
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What was the primary and counter stain in the acid-fast stain? |
carbol fuchsin (primary)methylene blue (counter- stain)
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What organism was used in the endospore stain? |
Bacillus megaterium(+)
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What were the primary and counter stains used in the endospore stain? |
malachite green (primary)safranin (counter stain)
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what is an endospore made of? |
protein keratin |
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what stain is this? |
simple stain |
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what stain is this? |
gram stain |
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what stain is this? |
capsule stain |
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what stain is this? |
acid-fast |
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what stain is this? |
endospore |
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The right side of the slide, shows a positive reaction for which biochemical test?
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catalase |
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which bio chemical test is this? |
oxidase |
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which biochemical test is this? Which tube is positive? Which tube is negative? |
Carbohydrate fermentation, yellow tubes are positive, red/pink is negative. |
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A carbohydrate fermentation test that turns yellow after 24-8 hours and produces bubbles should be recorded as ____________ |
positive for acid and gas |
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what biochem test is this? |
Kliger's iron agar. It is positive if it forms a dark precipitate. |
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what biochem test is this? What is positive and what is negative? |
Gelatinase. It is positive if it stays liquid when put in an ice bath. It is negative if it goes back to a solid. |
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What bichem test is this? |
biofilm |
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What biochem test is this? |
Casein Hydrolysis |
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What biochem test is this? |
Lipid hydrolysis. It is positive if a clear zone is formed. |
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What does Nitrate reduction test for? |
To see if the organism under anaerobic conditions can reduce nitrate to nitrite, or even further to nitrogen gas? |
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What does it mean if gas bubbles are present in the durham tube in the nitrate reduction test? |
That the organism is positive for nitrate reduction, If not gas is present then you move to step two. |
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How do you know if an organism is negative for nitrate reduction? |
If you perform all the steps and the medium turns red. |
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What is this bichem test? |
Nitrate reduction |
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What flagellar arrangement is this? |
Monotrichous |
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What flagellar arrangement is this? |
lophotrichous |
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What flagellar arrangement is this? |
Amphitrichous |
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What flagellar arrangement is this? |
Peritrichous |
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What is a bacteriphage |
A virus that infects bacteria |
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How do you focus the microscope |
•Lookingthrough the oculars, turn the coarse focus knob away from you •Whenyou see a blurry image, stop turning•Turnthe fine focus knob away from you until the image is clear
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Know the growth patterns |
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What was the purpose of the E.I. project |
To understand how to isolate, characterize, and identify an organism |
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what kind of growth medium did we grow our organisms on? |
TSA- Trypticase soy agar |
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At the very least, what things do bacteria need to grow? |
•nutrients,an energy source, and a suitable environment.
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What is the most important part of microscopy? |
contrast |
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Resolution |
•Theability to visualize two points as separate and distinct
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How do we carry the microscope? |
•Onehand at the neck/arm, the other hand under the base
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How is magnification adjusted on the microscope? |
by using a higher/lower power lens |
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How is resolution adjusted on the microscope? |
adjust the fine focus knob |
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how can contrast be adjusted on the microscope? |
adjust the condensor |
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for capsule stains, the background can be stained with a _______ stain and the cell body can be stained with a/an _______ stain |
acidic, basic |
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how do we sterilize the loops and needles? |
flames sterilization with bunsen burner |
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Indirect methods of enumerating bacteria |
–rely on the results of metabolic tests or other growth characteristics
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Direct methods of enumerating bacteria |
countindividual bacterial cells
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What does CFU stand for? |
colony forming units |
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Trueor False? All the hamburger suspensions are made of beef
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false |
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•Whatis the difference between spread and pour plates?
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With spread plates, you are spreading the molten agar with a hockey stick, and with a pour plate you are simply pouring molten agar into a plate so it just covers the bottom of the plate. |
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•Howdo you put out an ethanol fire in a Petri dish? |
you use a wet paper towel |
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•Whatis the number of countable colonies per plate?
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30-300 |
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•Whatwas the diluent for serial dilutions and control plates?
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0.75% NaCl |
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What does the catalase bio chem test test for? |
test for presence of catalase enzyme |
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What does the oxidase biochem test test for? |
The presence of cytochrome oxidase |
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What does the anaerobic respiration by nitrate reduction test for? |
Testsfor facultative anaerobes that can switch between aerobic respiration (reducingoxygen) and anaerobic respiration (specifically, reducing nitrate)
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What does urea hydrolysis test for? |
Testsfor the presence of urease, an enzyme that breaks down urea into ammonia andcarbon dioxide
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What does Kliger's Iron agar test for? |
Testsfor the production of hydrogen sulfide by the reduction of thiosulfate or bythe deamination ofcysteine
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What does the gelatinase bio chem test test for? |
Testsfor the presence of gelatinase, an enzyme that hydrolyzes gelatin
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What does the biofilm biochem test test for? |
Testsfor the ability to form biofilms on surfaces
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What does the lipid hydrolysis biochem test test for? |
Testsfor the presence of lipases, enzymes that hydrolyze lipids
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Eclipse/latent period |
Timebetweeninitial infection and the release of mature phage
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Burst size |
•Thenumber of newly synthesized, infectious virionsreleased from a single cell’s lysis (typically between 20 and 200)
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virion |
aninfectious version of a virus released from a cell
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Plaque |
•Aclear area on a lawn of host cells that represents the location of a singleT4-infected E. coli cell
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•Whatare lawn cells?
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layer of bacterial cells in soft agar that the bacteriophage will infect |
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burst size |
average number of phage particles released per infected bacterium |
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What phase of the T4 lytic cycle is happening at time zero? |
adsorption |
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What is pfu? |
plaque forming unit |
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diplococcus |
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streptococcus |
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tetrads |
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staphylococcus |
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What would the morphology be of a cell that is shaped between cocci and rods? |
coccobaccilli |
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diplobacillus |
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streptobacillus |
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palisading/palisades |
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What are spiral shaped cells called? |
spirilla |
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What are rod shaped cells called? |
bacilli |
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What does it mean if a bacteria is a wild type? |
It can synthesize tryptophan |
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What does it mean if a bacteria is a mutant type? |
It cannot synthesize tryptophan on its own. |
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What was the objective for the transformation lab? |
introducenaked DNA from lysed SD5 ontoa plate of SD6 in order to get transformation and growth.
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Positive and negative control for starch Hydrolysis |
+: Bacillus megaterium -: E. coli |
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Positive and negative control for starch Hydrolysis |
+: Bacillus megaterium -: E. coli |
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Positive and negative controls for Casein Hydrolysis |
+: Bacillus Megaterium -: E. Coli |
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Positive and negative controls for lipid Hydrolysis |
+: Serratia spp. -: Staphylococcus epidermidis |
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What bio chem test turns from green to blue if positive? |
Simmons Citrate |
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What biochem tests have control organisms |
Catalase, oxidase, lipid Hydrolysis, starch Hydrolysis, and Casein Hydrolysis |
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What are the positive and negative controls for the catalase test? |
+:staphylococcus epidermidis -: Streptococcus lactis |
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What is the control organism in the oxidase test |
Pseudomonas aeruginosa |
