Docstoc

Lab Schaeffer

Document Sample
Lab Schaeffer Powered By Docstoc
					                Lab #9
• Acid Fast Stain
• Endospore Stain
• Eosin Methylene Blue (EMB) Agar
                Acid Fast Stain
• Differential Stain
• Ziehl Neelsen (ZN) heat method
• Acid fast cells have higher differentiation for primary
  stain and resist decolorization by acid alchohol
• Mycolic acid in cell walls of acid fast cells
• Used to identify bacteria in the genus Mycobacterium,
  (ie. M. leprae, M. tuberculosis)
       Bacteria for acid fast
• Mycobacterium smegmatis
• Staphylococcus aureus
         Staining procedure
• Heat fix bacteria
• Carbolfuchsin –primary stain
• Steam heat enhances the entry of
  carbolfuchsin into cells
• Decolorization with acid alchohol
• Methylene Blue counterstain for acid fast
  negative stain
 Results: Acid Fast (reddish)
Non Acid Fast (blue or purple)
           Endospore stain
• Schaeffer Fulton method
• Differential stain
• Detect presence and location of spores
• Used for bacteria that form spores in the
  genus Bacillus and Clostridium
• Keratin is the protein in the outer covering
  of the spore
   Bacteria for Endospore stain
• Bacillus cereus
• Bacillus subtilis
         Staining procedure
• Heat fix bacteria
• Malachite Green –primary stain
• Steam to force malachite green into the
  spore
• Rinse with water
• Conterstain –Safranin
• Rinse with water
      Spores of Bacillus- green
Vegetative cells prior to sporulation- red
    Eosin Methylene Blue Agar
• Selective Media
• Contain peptone, lactose, sucrose, and dyes eosin Y
  and methylene blue
• Sugars provide fermentable substances to grow coliform
  bacteria
• Green sheen serves as an indicator of lactose or
  sucrose fermentation
• Non fermenters retain the normal color or the color of the
  media
Bacteria to inoculate EMB plate
•   Staphylococcus aureus
•   Escherichia coli
•   Enterobactor aerogenes
•   Salmonella typhimureum
 E. Coli and Enterobactor growing on EMB agar




• E. coli                Enterobactor
Green (D) coliform        Pink (pi) coliform
         Salmonella on EMB




• Salmonella no growth (P) colorless colonies