BIO chapter 3

  1. what are the five I's of culturing microbes
    • Inoculation
    • INcubation
    • Isolation
    • INspection
    • Identification
  2. what is inoculation
    adding small sample (the inoculum) into a container of medium
  3. Isolation=
    the separation of different microbes from each other
  4. colonies are
    visible masses of cells
  5. pure colonies=
    if colony is from a single cell. they will all be genetically identical (aSlo called axenic)
  6. incubation=
    when the sample is kept betweeen 20 - 40 degree celsius
  7. Mixed culture=
    has two or more identified species
  8. contaminated cultures=
    have unwanted microorganisms of uncertain identity
  9. three isolation methods are
    • streak plate technique
    • spread plate technique
    • pour plate technique
  10. goal of streak plating
    bacteria are diluted on a solid surface using inoculating loop to isolate colonies
  11. steps in spread plate=
    • dilutions performed beforehand in liquid broth
    • small volume is spread out on surface using hockey stick
    • cells present are separated from each other
  12. pour plate technique =
    • cultures are diltued before hand in liquid agar
    • poured into plates
    • colonies form in and on the agar
  13. media =
    what substances are displayed in
  14. media classifications
    • physical state
    • chemical comp
    • functional type
  15. physical states of media =
    • liquid 
    • solid (agar)
    • semisolid
    • reversible
  16. defined media =
    chemical comp is precisely known (synthetic)
  17. complex media =
    • one or more components is not chemically definable (nonsynthetic)
    • 5% yeast extract
  18. general purpose media =
    to grow as broad a spectrum of microbes as possible
  19. TSA =
    trypticase soy agar
  20. enriched media =
    contain growth factors to support the growth of fastidious bacteria ie blood agar, chocolate agar
  21. selective media =
    lets some grow but not others
  22. differential media =
    allow many microbes to grow but display visible differences (usually colors)
  23. Inspection and Identification
    using appearance as well as metabolism and sometimes genetic analysis or immunologic testing to identify the organisms in a culture.
  24. Resolution= 
    the ability to distinguish two adjacent objects or points from one another (resolving power)
  25. numerical aperature
    is how well the lens gathers light
  26. oil immersion lens does what
    improves resolution, shorter wavelengths and lower resolving power than without oil
  27. staining increases
  28. gram staining is 
    • the most universal diagnostic staining technique
    • differentiate microbes as gram positive or gram negative
  29. effect of wavelength on resolution
    smaller wavelengths = sharper image
  30. how does oil immersion improve resolution
    • immersion oil reduces refraction of light
    • more light is gathered
    • resolution improved - shorter wavelengths and lower resolving power than without oil.
  31. what does staining do to microbes
    increases contrast and sometimes increases size
  32. gram staining color = what
    • gram positive = purple
    • gra negative = red
  33. what is brightfield compound illumination
    • dark objects are visible against light background
    • light reflected off the specimen doesn't enter the objective lens
  34. dark field (phase contrast) =
    • light objects are visible on a dark background
    • light reflected off the specimen enters the objective lens
  35. fluorescence microscopy =
    • uses uv light
    • fluorescents substance absorbs UV light and emits visible light.
    • cells are stained with fuorescent dyes
  36. confocal microscopy =
    • uses fluorochromes (fluorescent dyes) an a lasar light
    • the laser illuminates each plan in a specimen to produce a 3-D image
  37. what is important to know about resolution
    the shorter the wave length the better (provied better resolution)
  38. simple stain =
    uses one dye
  39. differential stains =
    distinguishes between gram + and gram -
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BIO chapter 3