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51 Cards in this Set
- Front
- Back
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endospores |
protective structures that allow the cell to survive harsh conditions |
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what generas have the ability to form endospores |
Bacillus & Clostridium
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how long does the endospore formation take |
6-12 h |
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what is the vegetative cell called |
sporangium
the endospore is formed within the first park of this period ; when the spore is fully formed, the sporangium is sloughed off. |
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endospore staining |
a differential stain that can help distinguish between endospore formers and non formers |
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primary stain in endospore stain |
malachite green |
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mordant in endospore stain? |
heat |
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what does the heat do to the primary stain |
it drives the primary stain, malachite green, into both the endospore and any vegetative cells |
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decolorization with _____ removes the ______ dye from _______ cells & the sporangium of spore formers but not the endospore. |
water primary vegetative |
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counterstaining with ______ imparts a pink color to the ______ cells, ensuring they are visible during microscopic examination. |
safarin vegetative |
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Another word for acidic dye |
Negatively charged |
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_____ _____ is not involved in negative staining which means it's the best choice for determine the ____ of a cell . |
Heat fix Size |
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_____ _____ is not involved in negative staining which means it's the best choice for determine the ____ of a cell . |
Heat fix Size |
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What is negative staining procedure ? |
Mixing cells with the acidic dye and spreading them over the surface of a slide in a very thin layer. The chromophore of the acidic dye allows the dye to bind to the glass of the cell while being repelled by the negatively charged bacterial cells. This stains the background while leaving the bacterial cells unchanged. |
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Capsule |
Complex layer of sugars and proteins |
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What does a capsule do for a bacterial cell |
Aid the cell by helping it to resist dehydration , adhere to invasive devices such as catheters and initiate the formation of biofilms. |
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Capsule stain |
Two step process that's a combination of negative staining followed by simple staining. |
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Capsule stain |
Two step process that's a combination of negative staining followed by simple staining. |
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Steps of capsule stain |
In the first step , the acidic dyes nigrosin or India ink is used to blackout the background. Since these are negatively charged, they will adhere ( stay attached ) to the glass of the slide but be repelled by the negatively charged bacterial cells , leaving the cells & capsules colorless against a dark background.
Heat fixation kept to a minimum; excess heat can shrink the cells , resulting in a false negative identification of a capsule containing cell.
Second step : the basic dye crystal violet is used to stain bacterial cell. The capsule will not stain with either dye , visible as a clear halo between the cell and the background.
Result is background being gray , cell purple & a clear halo surrounding the cell which is the capsule. |
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Mycolic acid |
Complex lipid that inhibits the passage of aqueous dyes through the cell wall |
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Carbohlfuschin |
A dark red dye containing 5% phenol as the primary stain , this dye is lipid soluble |
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Carbohlfuschin |
A dark red dye containing 5% phenol as the primary stain , this dye is lipid soluble |
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The mordant for acid fast stain is ? |
Heating , driving the carbolfuschin , the primary stain in Acid fast stain into the cell |
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Decolonizer of acid fast stain ? |
Hydrochloride acid in ethyl alcohol
Cells that retain the red color of the carbolfuschin under these harsh conditions are called acid fast. While the non acid fast cells stay clear after this step |
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Decolorizer of acid fast stain ? |
Hydrochloride acid in ethyl alcohol
Cells that retain the red color of the carbolfuschin under these harsh conditions are called acid fast. While the non acid fast cells stay clear after this step |
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What is the counter stain for acid fast stain ? |
Methylene blue ; stains the non acid fast cells blue while the acid fast cells stay red |
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Acid fast stain is primarily used to detect members of what genus ? |
Genus : Mycobacterium , nocardia, and even protozoan parasites. |
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Acid fast stain is primarily used to detect members of what genus ? |
Genus : Mycobacterium , nocardia, and even protozoan parasites. |
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When is acid fast stain used |
When an infection by an acid fast organism is suspected |
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When staining the cells with a positively charged or basic dye, what does it do |
Increase the contrast between bacterial cells N the background got microscopic examination |
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How should a negative stain look like |
Cells are seen as light objects against a dark background. |
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Heat fixation - which causes cell shrinkage - is not involved in _______ _______ |
Negative staining |
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Inoculating loop is used with ? |
Liquid |
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Inoculating loop is used with ? |
Liquid |
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Inoculating needle used with ? |
Solid |
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Mucoid |
Sticky |
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Is anything inhibited in blood agar plate ? |
No |
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Hemolysis |
Destruction of red blood cells |
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In blood agar what is the differential agent |
Blood |
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Capsules cause what to be easily formed ? |
Biofilms |
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Capsules increase ? |
Pathogenicity |
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Isolated colony |
Separated from each other |
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Mac Conley agar plate selective agents are ? |
Bile salts , crystal violet |
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Mac Conley agar plate is selected for : |
Gram negative rod species |
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What will produce when an organism ferments a sugar ? |
Acid will produced Turns red |
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Differential media |
Can differentiate one organism from another by chemical reaction |
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Agents in Mac Conley agar plate / |
Lactose , neutral red |
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What red blood cells are used in blood agar plate |
Sheep red blood cells |
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What is the selective agent in mannitol salts agar (MSA) |
Nacl Sodium Chloride |
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What genus does MSA select for? |
Staphylococci |
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What is the pH indicator in MSA? |
Phenol red |
