Clin Lab 4: Microbiology techniques (Gram Staining)

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  1. Name the 4 reagents used in a gram stain in order of use:CV,GI,D,S
    • crystal violet
    • gram's iodine
    • decolorizer
    • safranin
  2. A substance that aids in the chemical reaction between the dye and bacteria. Making the dye absorb better.
  3. Name the mordant
    gram's iodine
  4. What is made of acetone or alcohol?
  5. Name the counter stain
  6. What is made of carbol fuschin?
  7. Fill in the steps specimen on glass slide
    2.air dry
    4.flood slide with crystal violet for 1 min
    • 3.heat fix
    • 5.rinse slide carefully under slowly running water
  8. When heat fixing what should you be sure to do?
    pass the slide through the flame several times
  9. When flooding the slide with crystal violet for 1 minute what should you be sure to do?
    cover the entire area with stain
  10. Fill in the steps
    6.flood stain with gram's iodine for 1 minute(cover entire slide with stain)
    • 7.rinse slide again slowly
    • 8.decolorize slide carefully with alcohol
  11. How long should decolorizer run?
    until the slide runs clear
  12. Fill in the steps
    10.flood slide with safranin(counter stain) for 30 sec
    • 9.immediately rinse once the slide runs clear after decolorizing
    • 12.blot slide carefully with paper towl
  13. How long is crystal violet applied to the slide?
    1 minute
  14. How long is iodine applied to the slide?
    1 minute
  15. How long is decolorizer applied to the slide?
    until it runs clear
  16. Should decolorizer be left to set on the slide?
  17. How long is safranin applied to the slide?
    30 seconds
  18. What powers are used under the microscope?
    • 10x
    • 40x
    • 100x oil immersion
  19. Why do gram + and gram - cells stain differently?
    the amount of peptidoglycan in their cell walls
  20. Peptidoglycan provides strength, but what is it made of?
    sugar and amino acids
  21. What cells stain purple?
    gram + bacteria and yeast
  22. Why do gram + cells stain purple?
    they have 5x's the amount of peptidoglycan and this absorbs the crystal violet
  23. What cells stain pink?
    gram - bacteria and host cells
  24. In short name the steps of gram staining for review:F-C-R-I-R-D-R-S-R-B
    • fix
    • crystal violet
    • rinse
    • iodine
    • rinse
    • decolorizer
    • rinse
    • safranin rinse
    • blot
  25. What bacteria has the thicker cell wall?
    gram + because of the peptidoglycan
  26. What outer layer do gram - bacteria have that gram + bacteria do not?
  27. What does LPS stand for?
    lippolysaccharide layer
  28. Where is the LPS?
    it sits on top of the cell wall and is a second membrane
  29. What advantage do gram - bacteria have since they have the LPS?
    harder to kill because it increases their resistance to antibiotics
  30. Name the 3 forms of bacteria
    • coccus
    • bacilli
    • spirillum
  31. GPCOC
    gram positive cocci
  32. GPROD
    gram positive rod
  33. GNCOC
    gram negative cocci
  34. GNROD
    gram negative rod
  35. What form of bacteria is rare?
  36. What is the leading cause of cystitis?
    gram - enteric bacilli
  37. pair
  38. gram + grape like cluster
  39. gram + chain
  40. cube of 8
  41. cluster of 4
  42. What 3 things can bacillus species look like?
    • long/wide
    • long/narrow
    • branched
  43. Mixed populations are harder to kill what should be used?
    broad spectrum abx (clavamox,baytril)
  44. Yeast can be what 2 shapes
    • budding
    • branching
  45. What are yeast called when they branch?
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Clin Lab 4: Microbiology techniques (Gram Staining)
2013-09-10 11:08:39

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