Question: Is Blood Agar Selective Or Differential Or Both?

Why is EMB Agar both selective and differential?

Eosin Methylene Blue (or EMB) Agar is a Selective & Differential Medium.

The selective and differential aspects are due to the dyes Eosin Y and Methylene Blue, and the sugars lactose and sucrose in the medium.

It is Selective because it encourages some bacteria to grow while inhibiting others..

Is blood agar selective or differential?

Blood Agar This medium can be made selective by the addition of antibiotics. This medium is differential because: Blood Agar tests for the production of hemolysin which breaks down red blood cells.

Is blood agar selective or differential quizlet?

Terms in this set (14) Blood agar is Differential and enrich. Beta-hemolysis is complete hemolysis. It is characterized by a clear (transparent) zone surrounding the colonies.

What is the difference between selective and differential media?

Selective and differential media are used to isolate or identify particular organisms. Selective media allow certain types of organisms to grow, and inhibit the growth of other organisms. … Differential media are used to differentiate closely related organisms or groups of organisms.

What is MacConkey Agar differential for?

MacConkey agar is a selective and differential culture medium for bacteria. It is designed to selectively isolate Gram-negative and enteric (normally found in the intestinal tract) bacilli and differentiate them based on lactose fermentation.

Is MacConkey agar selective or differential?

MacConkey agar is a selective and differentiating agar that only grows gram-negative bacterial species; it can further differentiate the gram-negative organisms based on their lactose metabolism.

What is the indicator in blood agar?

Phenol red is the pH indicator. Motility-Indole-Ornithine Agar: motility is indicated by the character of the growth in the butt of this tube.

What bacteria can grow on MacConkey Agar?

MacConkey agar is used for the isolation of gram-negative enteric bacteria. It is used in the differentiation of lactose fermenting from lactose non-fermenting gram-negative bacteria. It is used for the isolation of coliforms and intestinal pathogens in water, dairy products and biological specimens.

What bacteria does not grow on blood agar?

Blood agar is an enriched, bacterial growth medium. Fastidious organisms, such as streptococci, do not grow well on ordinary growth media. Blood agar is a type of growth medium (trypticase soy agar enriched with 5% sheep blood) that encourages the growth of bacteria, such as streptococci, that otherwise wouldn’t grow.

Is E coli Gram positive or negative?

E coli is a gram-negative bacillus that grows well on commonly used media. It is lactose-fermenting and beta-hemolytic on blood agar. Most E coli strains are nonpigmented. The image below shows Escherichia coli on Gram staining.

Why is blood agar differential?

A differential medium support the growth of any microbe but distinguishes them based on how they metabolize or change the medium. One example of differential medium is blood agar. Blood agar distinguishes microbes based on their ability to lyse red blood cells (RBCs), a property known as hemolysis.

Can bacteria grow in chocolate?

What happens during cocoa fermentation? Because the inner pulp of the bean is so acidic, not many bacteria can actually grow on it. However, yeasts and lactic acid bacteria just love this kind of environment. So, they grow and start metabolising the pulp.

What color is E coli on MacConkey Agar?

dark pinkPresumptive identification of E. coli was made based on its characteristic morphology colony on the selective medium MacConkey agar. Rapid lactose fermenting colonies of E. coli appear dry, donut shaped and dark pink in color and are surrounded with dark pink area of precipitated bile salts.

Which Agar is both selective and differential?

MacConkey Agar. This medium is both selective and differential. The selective ingredients are the bile salts and the dye, crystal violet which inhibit the growth of Gram-positive bacteria.

Why is blood agar not a selective media?

Blood agar is an enriched medium that provides an extra rich nutrient environment for microbes. Therefore, BAP is not a selective growth medium, since it supports the growth of a wide range of organisms.

Is chocolate agar selective or differential?

Chocolate Agar supplemented with bacitracin is a selective medium used to improve the primary isolation of H. influenzae from specimens containing a mixed flora of bacteria and/or fungi.