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21 Cards in this Set
- Front
- Back
nonspecific stain |
-react with all microbes in an identical fashion -useful solely for increasing contrast so that morphology, size, and arrangement of organisms can be determined |
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specific stain |
give varying results depending on the organism being treatment |
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stains are chemicals containing |
chromophores |
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chromophores |
groups that impart color |
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specificity is determined |
by their chemical structures |
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basic dye |
a stain that is cationic and will react with material that is negatively charged |
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surface of bacteria at a neutral pH is somewhat _________charged and will attract _________ dyes |
negative charge basic dyes |
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basic dye examples |
crystal violet safranin basic fuchsin methylene blue |
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acid dyes |
-negatively charged chromophores and are repelled by the bacterial surface -stain the background and leave the microbe transparent |
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acid dye examples |
nigrosine and congo red
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simple stain |
when a single stian is used |
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preparation of a smear |
a thin layer of specimen dried and fixed onto the slide before it is stained |
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excess unreacted stain must be removed from background before bacteria can |
be seen in microscope |
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the stain is applied to |
an immobilized organism |
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any stain that reacts will also be _________ onto the slide and _______ stain can be washed off |
immobilized; unreacted |
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simple stain cultures |
corynbacterium xerosis(slant) staphylococcus epidermidis(slant) klebsiella pneumoniae or E.coli (slant) |
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what effect may heat fixation have on microbe |
it could kill it |
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advantage of simple |
stains everything |
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- of simple stain |
can't differentiate between bacteria |
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negative stain |
able to identify specific bacteria and differentiate bacteria gives a background for the positive stain |
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information |
location of bacteria or presence of it |