Selective Differential Media Flashcards
What is MSA selective for?
Isolation of salt tolerant Gram (+)
What is MSA selective against?
Salt inhibits the growth of salt sensitive gram (+) and gram (-)
What is the selective material for MSA?
Salt
What is the differential positive for MSA?
Phenol red color change to yellow= manitol fermentation
What is the differential negative for MSA?
Red coloration= no mannitol fermentation
What is the differential material for MSA?
Mannito with phenol red as the pH indicator
What is the agar type for CNA?
Colistin-Nalidixic Acid with sheep red blood cells agar
What is CNA Selective for?
Isolation of Gram (+)
What is CNA selective against?
Gram (-)
Why is CNA Selective against Gram(-)?
Due to the action of the colistin-nalidixic acid on outer membrane
What is the selective material of CNA?
Colistin-nalidixic acid
What is the differential positive of CNA?
Alpha (Green halo)=incomplete hemolysis
Beta (Clear halo)=complete hemolysis
What is the differential negative of CNA?
Gama (no halo)=no ability for hemolysis
What is the differential material of CNA?
Sheep red blood cells
What is the Agar type of EMB?
Eosin-Methylene Blue agar
What is EMB selective for?
Isolation of Gram (-)
What is EMB selective against?
Aniline dyes inhibit the growth of Gram (+) by interfering with the function of the peptidoglycan layer
What is the selective material of EMB?
Aniline dyes
What is the differential positive for EMB?
Purple (low) to metallic green sheen (high)= lactose fermentation
What is the differential negative for EMB?
No color to pale lavender
What is the differential material for EMB?
Lactose with eosin dye and methylene blue used as color indicators
What is Macconkey selective for?
Isolation of gram (-)
What is MacConkey selective against?
Crystal violet and bile salts inhibits the growth of Gram (+) by interfering with the function of the peptidoglycan layer
What is the selective material of MacConkey?
Crystal violet and bile salts
