Flashcards
Microbiology Lab Final
Cards in this deck (96)
- 1how many colonies are on a countable plate30-300 colonies
- 2what does TFTC mean"To few to count"
< 30 colonies - 3what does TNTC mean"To numerous to count"
> 300 colonies - 4CFU formula(number of colonies x dilution factor) / volume of the culture plate
- 5Original Cell Density (OCD) formulaCFU/OSV
OSV --> Original sample volume - 6original sample volume (OSV) formulavolume×dilution factor (if not provided assume df=1)
- 7V1D1 = ?V2D2
- 8what is the difference between disinfectant and antiseptic?disinfectant: for use on inanimate objects
antiseptic: for use on living tissue - 9what kind of PPE did we use in lab?lab coat
goggles
gloves - 10why are aseptic techniques important?to prevent contaminating:
yourself
your sample
your environment - 11what is the benefit of using a broth?obtaining a lot of cells in a short period of time
- 12what is the benefit of using a slant?good for storage if you just need to keep a fresh culture
- 13what is the benefit of using an agar plate?isolating a single colony (streaking)
- 14formula for total magnificationm = m1 x m2
m --> magnification
m1 -->linear mag of objective lens
m2 --> linear mag of eyepiece - 15what is the limit of resolution?the value at which you can distinguish 2 points/pixels in image from each other
- 16is a higher or lower limit of resolution (LOR) better?LOWER for better resolutio/clarity
- 17Limit of resolution (LOR) formulawavelenth (lambda)/ NAobjective + NAcondenser
- 18what is a benefit to negative stainingno heat fixing --> can allow you to get a better idea of cell shape/morphology because it is alive
- 19what is the differential component of the Mannitol salt agar?mannitol
only looking for organisms that can metabolize mannitol - 20what is the selective component in mannitol salt agar?high salt content, selects for gram positive and organisms that can grow in high salt conditions
- 21what causes the color change in mannitol salt agar?if an organism can utilize mannitol, it causes a pH change which results in a color change
- 22What are the selective components in MacConkey agar?bile salts and crystal violet
selects for gram negative - 23What is the differential components of MacConkey agarthe ability to utilize lactose
- 24what causes the color change in MacConkey agar?if the organism can ferment lactose, it will turn pink
pH > 6.8 will be colorless - 25Why did we use two tubes for the OF glucose test?one with mineral oil on top to cut off oxygen supply and see if the organisms were anaerobic
- 26What was the effect of a lid on the plate during the UV testUV was unable to damage bacteria DNA through the lid
- 27what are the ways bacteria can repair UV damage from sunlight?photolyases (activated by light/light repair)
if active photolyases, bacteria should survive and repair itself from damage
dark repair (can happen in absence of light) - 28how many organisms are tested on one plate in the Kirby-Bauer methodone organism
- 29how do you determine resistance/susceptibility with Kirby-Bauer method?measure zone of inhibtion and compare it to the zone chart
- 30how do you determine if an antimicrobial is bactericidal or bacteriostaticmake a streak plate with an inoculating loop swiped on the zone of inhibition
bactericidal --> no growth
bacteriostatic --> growth - 31What is the MIC?minimum inhibitory concentration. the minimum amount of antibiotic thatwill prevent growth. located at the edge of the ZOI
- 32what is the difference between BSL-1 and BSL-4BSL-1: not known to consistetnly cause disease in healthy adults, requires less precautions
BSL-4: dangerour that pose high risk of light-threatening disease, require more precautions - 33what are aspetic techniques/Putting test tubes over bacti-cinerator betwee uses
- 34what elevation is this?plateau
- 35what elevation is this?umbonate
- 36what elevation is this?convex
- 37what elevation is this?flat
- 38what elevation is this?raised
- 39what elevation is this?raised, spreading edge
- 40what elevation is this?flat, raised margin
- 41what elevation is this?growth into medium
- 42what is the description for these type of margins?smooth, entire
- 43what is the description for these type of margins?rhizoid
- 44what is the description for these type of margins?irregular (erose)
- 45what is the description for these type of margins?lobate
- 46what is the description for these type of margins?filamentous
- 47what is the description for these whole colony shapes?rhizoid
- 48what is the description for these whole colony shapes?irregular
- 49what is the description for these whole colony shapes?filamentous
- 50what is the description for these whole colony shapes?round
- 51—no growth/clear
- 52—sediment
- 53—pellicle
- 54—flocculent
- 55—turbid/cloudy
- 56how to find size of specimenfind spot where rulers line up, stage distance over ocular distance (200um/10OU)= 20 um/OU, then measure speciment in OU and multiply it by 20um/OU to get measurement in um
- 57ocular micrometer unitsarbitrary units (OU)
- 58stage micrometer unitsum
- 59basic/simple stainstains negatively charged molecules
uses just crystal violet
heat fixes - 60steps of gram stainingfixation --> crystal violet --> iodine treatment --> decolorization --> counter stain with safranin
- 61what happens if you don't do thee decolorization step long enough?the crystal violet may not get all the way out of the gram negative cells and can result in gram negative cells remaining purple and appearing gram positive
- 62what colors are gram positive vs. negative cells after gram staininggram positive --> purple
gram negative --? pink - 63what allows for the different staining between gram negative and positive?the amount of peptidoglycan in their cell walls
- 64—fermentation with acid and gas ends products
A/G
- 65—fermentation with acid end products; no gas products
A/-
- 66—no fermentation
-/-
- 67—degradation of peptone; alkaline end products
K
- 68if an organism can break down sucrose or lactose, what can we infer about its ability to break down glucose?theoretically it should be able to break down glucose
- 69if an organism can break down sucrose or lactose, what can we infer about its ability to break down the otherwe can't
this does not necessarily mean that it can break down the other - 70why does an organisms ability to breaj down sucrose or lactose affect its ability to break down glucose?glucose is a component of both lactose and sucrose
- 71—oxidation and ferentation or fermentation only
F1 or O-F
- 72—oxidation
O
- 73—no sugar metabolism
N
- 74sealed tube: green or blue unsealed: any amount of yellowoxidation (O)
- 75sealed: yellow throughout unsealed: yellow throughoutoxidation and fermentation or fermentation only
(O-F or F1) - 76sealed: slighlty yellow at top unsealed: slightly yellow at topoxidation and slow fermentation or slow fermentation only
(O-F or F1) - 77sealed: green or blue unsealed: green or blueno sugar metabolism; organism is nonsaccharolytic
(N) - 78—coccus
- 79—diplococci
- 80—streptococci
- 81—sarcina
- 82—tetrad
- 83—staphylococci
- 84—bacillus
- 85—coccobacillus
- 86—diplobacilli
- 87—streptobacilli
- 88—palisades
- 89—spirochete
- 90—corkscrew form
borrelia burgdorferi
- 91—filamentous
- 92—comma form
bdellovibrio
- 93—enlarged rod
fusobacterium
- 94—vibrio
- 95—helical form
helicobacter pylori
- 96—club rod
corynebacteriaceae
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- Biology Flashcards on Microbiology Lab Final, created by Riley Marasco on 02/05/2024.
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