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Micro Mini Practical 2

Ami G. Microbiology Inglés 47 fichas

Fichas del conjunto (47)

1—Staphylococcus aureus: Gram positive
(after applying crystal violet)
2—Escherichia coli: Gram negative
(after applying crystal violet)
3—Staphylococcus aureus: Gram positive
(after Gram's iodine)
4—Escherichia coli: Gram negative
(after Gram's iodine)
5—Staphylococcus aureus: Gram positive
(after acetone alcohol decolorizer)
6—Escherichia coli: Gram negative
(after acetone alcohol decolorizer)
7—Staphylococcus aureus: Gram positive
(after Safranin counterstain)
8—Escherichia coli: Gram negative
(after Safranin counterstain)
9In order, what are the 4 steps in the staining procedure?Smearing
Air drying
Heat fixing
Staining
10Broth samples are easier to prepare, but...harder to see
11Agar samples are harder to prepare, but...easier to see
12To smear on an Agar sample, you have to...put a drop of water on the slide
13Heat fixing is used toaffix the bacteria to the slide
14To heat fix a slide...pass it over the flame, don't hold it there.
Overheating will cause it not
to stain correctly
15Gram Stain Procedure: 4 stepsCrystal Violet
Gram's Iodine
Acetone Alcohol decolorizer
Safranin counterstain
Rinse w/water after each step
16Ziehl-Neelson Acid-Fast Stains looks for the cell walls of what two types of bacteria?Mycobacterium
and
Nocardia
17Ziehl-Neelson Acid-Fast Stains steps:Steaming tray
Carbolfuchsin ZN stain (5 min)
Acid-alcohol decolorizer
Loefflers methylene blue counterstain
18Mycobacterium and Nocardia in an acid-fast stain will turn what color and why?Pink due to the carbolfuchsin dye
19antibiotic resistant bacteria and chemical resistance bacteria are gram ________?Gram negative
20environmental resistant bacteria heat pH osmotic pressure are gram __________?Gram positive
21The difference in gram stains is due to...the difference in the thickness of the cell walls of the bacteria being stained
22Specific structures like flagella and capsules are seen usingspecial stains
23Gram stains, acid-fast stains, & endospore stains are all...differential stains
24Endospore stains use ______ as the primary stain?Malachite green
25What stain uses water as the decolorizer?Endospore
26Endospore stain steps:Smear, air dry, heat fix
Stain w/ malachite green
(water as decolorizer)
Safranin as decolorizer & counterstain
27—Bacillus subtilis
(endospore stain)
28—Endospore stain
Left - water rinse, followed by Safranin
Right - water rinse, no Safranin
29Capsule stains are viewed under what magnification?100x w/oil
30What stain does not use heat fix?Capsule stain bc it would
destroy the capsule
31Malachite Green Safranin Crystal Violet & Methylene Blue are what types of dyes?Cationic dyes (positive sticking to negative particles)
Bacteria have a negative charge, making cationic dyes best
32Eosin and acid fuchsin are what types of dyes?anionic dyes (negative sticking to positive particles)
33Refers to placing a thin layer of the organism on a slideSmear
34Allows the organism to dry through evaporationair dry
35allows the organism to be attached to the slidefixing
36Who developed the Gram StainHans Christian Gram (late 1800s)
37What is the very first thing done before Gram Staining?Streaking for isolation
38What acts as a mordant (dye fixative)?Gram's Iodine
39How can time affect a gram stain?If decolorizing for too long, all bacteria would decolorize and would make it a false gram negative.
If too short, not sufficient, so false gram positive
40—Capsule stain
41How can age affect a gram stain?Cultures older than 24 hours decolorize easier and are falsely Gram negative
42How can heat affect a gram stain?The cell wall can be destroyed which leads to a false gram negative
43What two bacteria normally construct an endospore?Bacillus & Clostridium
44Tetanus, botulism, gangrene, & anthrax ae caused by what bacterias?Bacillus & Clostridium
45The pink bacteria seen after an acid-fast stain are read as gram negative? True or FalseFalse
46Old cultures tend to stain Gram negative? True or FalseTrue
47In the capsule stain, the capsule appears blue in color due to the use of Loafers methylene blue as the primary dye. True of False?False