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27 Cards in this Set
- Front
- Back
A properly prepared smear |
Withstands the washings required during the staining procedure (i.e. the bacteria doesn’t wash off) Is not too thick (this can inhibit proper staining throughout) Does not have excessive heat fixing (this can cause distortion and shrinkage of the cells) |
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Heatfix |
passing the slide sample side up through the flame 3-4 times. |
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why heat fix |
kill organism so its not potential pathogen keeps bacteria from being washed off with oil exposes stainable properties of cell by denaturing proteins |
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coccus |
round |
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bacillus |
rod shape |
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spiral |
twists |
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diplo |
pairs |
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strepto |
chain like |
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staphylo |
cluster |
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spirillum |
rigid spirals |
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spirochete |
flexible spirals |
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simple stain |
color microbe to examine shape/ arrangement; 1 dye only |
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basic dye |
it has a positive charge; are attracted to negative charge created by the phospholipids in the membranes. |
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methylene blue |
used for slides with yeast |
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crystal violet |
for most slides. |
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common dyes in simple stains |
crystal violet methylene blue safranin |
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Differential stain |
•Stain technique that differentiates between 2 different types of cellular structures. |
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differntial stain is used to determine |
–Size –Morphology –Arrangement |
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Gram + |
blueish purple |
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Gram - |
pinkish red |
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gram stain technique |
1)Next add Primary (1°) stain = first stain applied:CrystalViolet (1 min)
3)Wash slide with distilled water 4)Next add Mordant: chemical that increases size and interaction of CV with peptidoglycan:Iodine (1 min) 5)Wash slide with distilled water● 6)Add Decolorizing agent (acetone alcohol)2-4 drops running down slide over 2 secs:(removes1° stain Crystal Violet from Gram (-) cells)● 7)Wash slide with distilled water 8)Add Counterstain:Safranin (2min)(The second stain is applied to stain decolorized cells) Wash with distilled water, blot, and observe via oil immersion |
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endospore |
Special stain that identifies the presence of a structure dormant form of bacterium that allows survival in poor environment |
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Schaeffer Fulton Endospore Stain Procedure |
1.Prepare heat-fixed smear on clean slide. 2.Apply malachite green while steaming, 5 min. DO NOT let it dry out. 3.Cool slide for 2 min. Gently rinse w/distilled water. 4.Counterstain w/ safranin 1 min; rinse w/ water 5.Gently blot w/ bibulous paper 6.Observe under oil immersion |
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Differential stain type |
Acid Fast Stain |
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Mycobacterium and Nocardia |
are AF (+) because cellwall contains waxy lipid called mycolic acid |
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Mycolic Acid: |
-givescells higher affinity for carbolfuschin stain -makescells resistant to decolorization by acid alcohol solutions |
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Ziehl Neelsen |
1.Prepare heat-fixed smear on clean slide.
•Use separate aseptic transfers to add Mycobaterium laticola (mix into drop first and very thoroughly) andStaphylococcus aureus to the slide. 2.Applycabolfuchsinwhile steaming, 5 min.DO NOT let it dry out (add stain if drying out). 3.Cool30 sec and rinse w/ distilled water. 4.Decolorizew/ acid alcohol until run-off is clear (15-20sec, CAUTIONACID!) 5.Counterstainw/ methyleneblue (1 min) 6.Rinsew/ distilled water 7.Gentlyblot w/ bibulous paper 8.Observeunderoil immersion |