What is eosin methylene blue agar used for?
Eosin methylene blue agar (EMB) is a selective and differential medium used to isolate fecal coliforms. Eosin Y and methylene blue are pH indicator dyes which combine to form a dark purple precipitate at low pH; they also serve to inhibit the growth of most Gram positive organisms.
What type of media is eosin methylene blue?
Eosin Methylene Blue (EMB) agar is a differential microbiological medium, which slightly inhibits the growth of Gram-positive bacteria and provides a color indicator distinguishing between organisms that ferment lactose (e.g., E. coli) and those that do not (e.g., Salmonella, Shigella).
Is eosin methylene blue agar a selective or differential media?
EMB agar contains peptone, lactose, sucrose, and the dyes eosin Y and methylene blue; it is commonly used as both a selective and a differential medium. EMB agar is selective for gram-negative bacteria.
What happens if you mix eosin and methylene blue?
What should be the result of staining a bacterial smear with a mixture of eosin and methylene blue? Methylene blue–is basic The smears background would turn out red while the cells would turn out blue. What are differential stains?
Which media is selective?
Selective medium contain particular ingredients that inhibit the growth of certain microbes. An example of a selective medium is MacConkey agar. It contains bile salts and crystal violet, which interfere with the growth of many gram-positive bacteria and favor the growth of gram-negative bacteria.
Does Enterobacter aerogenes grow on EMB?
coli produces acids by fermentation, the acids can not change the pH of the modified-EMB media due to its high buffering capacity. Similarly, Enterobacter aerogenes (now Klebsiella aerogenes), a lactose fermenter which generally does not produce green sheen, produced green sheen on an unbuffered EMB medium.
What are the 3 possible results on an EMB plate?
What are the 3 possible reaction results on a Blood Agar Plate? Alpha Hemolysis= green halo around colony. Beta Hemolysis= clear zone around colony. Gamma Hemolysis= normal looking colony.
Is EMB defined or undefined?
EMB agar is an undefined medium. It contains multiple ingredients in which the composition is unknown, including beef extract and pancreatic digest of gelatin. Undefined media allows for all bacteria to grow making it desirable.