Quick Answer: Can A Media Be Both Selective And Differential?

Why is MacConkey agar selective as well as differential quizlet?

Why is MacConkey agar selective as well as differential.

It’s selective to gram negative enteric bacteria because it contains bile salts, which inhibit most gram positive bacteria.

It also contains lactose, which differentiates between gram negative lactose fermenter and gram negative non-fermenters..

Is mannitol salt agar selective or differential?

Mannitol Salt Agar (MSA) This type of medium is both selective and differential. The MSA will select for organisms such as Staphylococcus species which can live in areas of high salt concentration (plate on the left in the picture below).

Can media be selective and differential?

Selective media generally selects for the growth of a desired organism, stopping the growth of or altogether killing non-desired organisms. Differential media takes advantage of biochemical properties of target organisms, often leading to a visible change when growth of target organisms are present.

What is the difference between selective and differential?

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.

Is TSA selective or differential?

TSA (Trypticase Soy Agar) and NA (Nutrient Agar) are General Purpose Media that are not selective or differential, their purpose is simply to grow many types of bacteria cheaply. Here we will use a general purpose media to compare the growth on the selective and differential media.

Is chocolate agar selective or differential?

Chocolate agar, a differential medium for gram-positive cocci.

What does E coli look like on MacConkey Agar?

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.

Why is MacConkey Agar considered both differential and selective?

MacConkey Agar (MAC) is a selective and differential medium designed to isolate and differentiate enterics based on their ability to ferment lactose. Bile salts and crystal violet inhibit the growth of Gram positive organisms. Lactose provides a source of fermentable carbohydrate, allowing for differentiation.

Is blood agar selective or differential or both?

Blood agar is a differential medium that distinguishes bacterial species by their ability to break down the red blood cells included in the media. Blood agar is often used to distinguish between the different species of pathogenic Streptococcus bacteria.

What is an example of selective media?

Examples of selective media include: Eosin methylene blue contains dyes that are toxic for Gram-positive bacteria. … MacConkey agar is for Gram-negative bacteria. Hektoen enteric agar is selective for Gram-negative bacteria.

Why is EMB 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.