Table of Contents
What selective media includes?
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.
Which media is not selective media?
Differential media takes advantage of biochemical properties of target organisms, often leading to a visible change when growth of target organisms are present. Differential media, unlike selective media, does not kill organisms.
Which of the following is not an example of selective media?
Which of the following is not an example of selective media? Explanation: Tryptic Soy is an example of broth which is used in broth formula. Mannitol agar, MacConkey’s agar, crystal violet blood agar, Thayer Martin agar, etc.
How do you make selective media?
Any medium can be made selective by addition of some inhibitory substances or altering its property. Some selective media also behave as indicator media. Various techniques are employed to make a medium selective. Name of the medium Selective for Chemical Mannitol Salt Agar, Salt Milk Agar S.aureus 10% NaCl.
Is Mac 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 are selective and differential media and how do they differ?
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 chocolate agar selective or differential?
Chocolate Agar is an enriched general- purpose medium that supports the growth of most fastidious and non-fastidious organisms. Because it is a non-selective medium, resident flora from clinical specimens may overgrow potential fastidious pathogens, such as Neisseria species.
What are the two most selective media?
Hektoen enteric agar is selective for Gram-negative bacteria. HIS-selective medium is a type cell culture medium that lacks the amino acid histidine. Mannitol salt agar is selective for gram-positive bacteria and differential for mannitol. Xylose lysine deoxycholate is selective for Gram-negative bacteria.
Is blood agar selective?
Blood Agar Is Not a Selective Medium If a bacterial growth medium is selective, that means that it grows only certain types of microbes while inhibiting the growth of other types of microbes. Blood agar is an enriched medium that provides an extra rich nutrient environment for microbes.
Is nutrient agar a selective media?
Nutrient agar is a general-purpose media that is mostly used for routine culture or to ensure prolonged survival of microorganisms. It is one of the most important and commonly used non-selective media for the routine cultivation of microorganisms.
Is TSA selective or differential?
Tryptic Soy Agar (TSA): a general purpose, non-selective, non-differential, supportive medium that supports growth of all microorganisms that do not require special nutrients.
Is starch agar selective or differential?
Starch agar is a differential medium that tests the ability of an organism to produce certain exoenzymes, including a-amylase and oligo-1,6-glucosidase, that hydrolyze starch.
What is the difference between enrichment media and selective media?
Enriched media contain the nutrients required to support the growth of a wide variety of organisms, including some of the more fastidious ones. Selective media are used for the growth of only selected microorganisms.
Why is MSA selective and differential?
Mannitol Salt Agar (MSA) is a selective and differential medium. The high concentration of salt (7.5%) selects for members of the genus Staphylococcus, since they can tolerate high saline levels. Organisms from other genera may grow, but they typically grow very weakly.
How is a culture media made selective with example?
Selective media – Used for the growth of only selected microorganisms. For example, if a microorganism is resistant to a certain antibiotic, such as ampicillin or tetracycline, then that antibiotic can be added to the medium in order to prevent other cells, which do not possess the resistance, from growing.
Is pea selective or differential?
PEA agar is a selective medium that permits the growth of gram-positive cocci while inhibiting most gram-negative organisms.
Which media are selective and differential quizlet?
For what is MacConkey Agar selective and differential? Selective: for Gram-negative bacteria because bile salts and crystal violet inhibit the growth of Gram-positive bacteria. Differential: based on ability to ferment lactose (bacteria that can ferment lactose cause a drop in pH which turns indicator pink).
Is eosin methylene blue agar selective or differential?
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.
Why is differential media typically inoculated with isolated colonies?
Differential media is typically inoculated with isolated colonies that have been previously cultured on general growth media because it allows the growth of certain bacteria. These organisms can be visually differentiated from biochemical reactions from different species or groups.
Is LB agar selective or differential?
Blood Agar Plates It is an enriched, non-selective differential medium that supports growth of a variety of bacteria and can detect hemolytic activity of the microorganism.
Is Thayer Martin Agar selective or differential?
Thayer-Martin agar is a selective medium used for the isolation of gonococci (Neisseria gonorrheae) from specimens containing a mixed flora of bacteria and/or fungi e.g. urogenital specimen. Modified Thayer-Martin (MTM) agar is a GC agar base containing vancomycin, colistin, nystatin, and trimethoprim lactate (VCNT).
Is mannitol salt agar selective or differential?
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). The differential ingredient in MSA is the sugar mannitol.
Why sheep blood is used in blood agar?
Sheep blood has been preffered source in the Blood agar due to the fact that sheep RBCs are most sensitive to the the hemolytic toxins released by bacterial cells thus causing hemolytic zones around the colonies over the period of time.
What are types of media?
The three types of media are commonly known as news media, social media, and web media, but you might also see them referred to as earned media, shared media, and owned media. Some other forms of modern media are print media, television, movies, and video games.
Is lactose broth selective or differential?
The selective ingredients are the bile salts and the dye, crystal violet which inhibit the growth of Gram-positive bacteria. The differential ingredient is lactose.
What are the 3 main types of microbiological culture media?
Liquid, semisolid and solid media are routinely used for growth of micro-organisms.
