Advantages and Disadvantages of Selective Media
- Growing Environment. The advantage of using selective media is the ability to control what will and will not grow on a particular culture plate or petri dish.
- Feedback. ...
- Isolating Positive Growth. ...
- Growth Variation. ...
What is the difference between a media and selective media?
A media in microbiology is used grow micro organisms like bacteria or Fungai. Selective media generally used to isolate a particular type of any organism. That selective media is an ideal media which favors growth of a particular type of organism and, if there is possibility, selective media also discourage the growth of other unwanted organisms.
How do selective media affect the growth of cells?
Though selective media provide important information on those chemicals that prevent or hinder growth of an organism’s cells, they cannot provide much data on how the growth of those cells can vary based on different chemicals and environments. In this way, selective media act as an on/off switch; either the cells grow, or they do not.
What can be added to media to create a selective environment?
For example, if a certain microbe is resistant to aparticular antibiotic (e.g., novobiocin), then that antibiotic can be added to the medium in order to prevent other organisms, which are not resistant, from growing. Likewise, other chemicals can be addedto media to create a selective environment.
What are the limitations or disadvantages of selective media?
This limitation or disadvantage of selective media requires the further study of a specific organism in a differential medium. Selective media provide immediate feedback on how an organism’s cells interact with any controlled chemical or substance introduced into the media.
Why is selective and differential media important?
Key Points. 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 benefit of using selective media when trying to isolate bacteria?
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.
What is the purpose of differential media?
Differential media contain compounds that allow groups of microorganisms to be visually distinguished by the appearance of the colony or the surrounding media, usually on the basis of some biochemical difference between the two groups.
What is the purpose of selective media quizlet?
The purpose of selective media is to isolate specific types of bacteria. Selective media contain chemicals that kill off some bacteria while helping other bacteria thrive.
What is the purpose of using selective media and differential media in microbiology?
Selective media are used to isolate a particular type of microorganism by giving a specific condition for the growth of that particular microorganism. Differential media are used to identify and differentiate microorganisms from a closely-related group with the help of unique growth patterns.
What is the application of selective medium?
Selective media are 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 to prevent other cells, which do not possess the resistance, from growing.
What is the difference between selective media and common media?
Selective media are the culture media designed for the growth of a selected organism while inhibiting the growth of other microorganisms. Differential media are the culture media designed to distinguish microorganisms from one another by visible growth characteristics.
What is selective culture media?
A selective culture medium is used to isolate a particular bacterial species or genus. After the addition of a number of inhibitors to the culture medium, the objective of this type of medium is to eliminate unwanted microbial flora.
What is selective media in microbiology quizlet?
What is the definition of a Selective Media? A Selective Medium is a culture medium designed to allow the growth of some kinds of organisms, but not others.
What is the importance of selective and differential media in medical microbiology quizlet?
What is selective media? Allows the growth of some organisms while inhibiting the growth of others. What is differential media? Differentiates closely related organisms or groups of organisms based on the organism's biochemical characteristics.
Which of the following describes selective media?
What is the definition of selective media? Selective media incorporate chemical substances that inhibit the growth of one type of bacteria while permitting the growth of another.
What is the difference between selective and differential media quizlet?
Selective media allows for the growth of specific organisms, while differential media is used to distinguish one organism from another.
What agar is recommended for isolation of Gram positive bacteria?
PEA agarPEA agar is a selective medium that is used for the isolation of gram- positive Staphylococcus species andStreptococcus species from clinical specimens or specimens that contain mixtures of bacterial flora (2).
Why do we consider MacConkey agar a differential and a selective medium?
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.
Which of the following is a selective medium for isolation of Neisseria gonorrhoeae?
GC-LectGC-Lect, a new selective medium for the isolation of Neisseria gonorrhoeae which contains five antimicrobial agents, was evaluated with stock cultures and with 500 clinical specimens.
Is blood agar selective or differential briefly explain?
Blood agar is differential. It contains red blood cells (commonly 5% sheep blood) and indicates whether hemolysis has occurred in a culture media c...
What are two examples of selective media?
Two examples are MacConkey Agar and Eosin Methylene Blue (EMB) agar. However, there are others, which are Hektoen Enteric (HE) agar, Xylose Lysine...
What is the difference between differential and selective media?
The addition of ingredients in selective media results in the inhibition and/or growth of organisms, while the ingredients in a differential media...
What are the characteristics of selective media?
They contain the ingredients needed for certain organisms to survive while inhibiting unwanted organisms from growing. To do this they could contai...
What is an example of differential media?
Differential media indicates the degree or ability of a biochemical property in a specimen culture media. This is usually due to the addition of a...
What is selective media in microbiology?
Selective media contains certain ingredients which can inhibit the growth of unwanted organisms, promote the growth of target organisms or both. Se...
Culture Media
In order to study bacteria in a lab, it needs to be grown. By doing so, researchers can view the bacteria through a microscope and identify various biochemical pathways through testing and analysis. They use the term culturing when they want to grow and isolate bacteria for further study.
Differential Media
Differential media, also known as indicator media, is a type of media (usually of a solid or semi-solid consistency) used to distinguish between bacterial cultures based on their biochemical properties.
Selective Media
It is very common to find a large number of bacterial species in any one sample, however when looking to analyze a specific bacterial species or type of micro-organism scientists need to be able to view it in isolation on a medium. This means, researchers would need to separate the target organism from the rest. To do this, selective media is used.
What is selective media?
Selective media are designed to inhibit unwanted commensal or contaminating bacteria and help to recover pathogen from a mixture of bacteria. While selective media are agar based, enrichment media are liquid in consistency. Various approaches to make a medium selective include addition of antibiotics, dyes, chemicals, ...
What is differential media?
Differential media are bacteriological growth media that contain specific ingredients that allow to distinguish selected ] Selective media are designed to inhibit unwanted commensal or contaminating bacteria and help to recover […] Enrichment media are liquid media that also serves to inhibit commensals in the clinical specimen. […]
What is the selective medium used to recover N. gonorrhoeae?
Thayer Martin Agar used to recover N. gonorrhoeae contains Vancomycin, Colistin and Nystatin.Mannitol Salt Agar and Salt Milk Agar used to recover S.aureus contain 10% NaCl.
What is enrichment media?
Enrichment Culture Media. Enrichment media are liquid media that also serves to inhibit commensals in the clinical specimen. ] Preservation Culture Media. It contains all the basic nutrients required for microbial growth and is used to preserve […] Chocolate Agar.
What is EMB used for?
Used for growth of only selected microorganisms. Selection by. Adding antibiotics, prevents the growth of other cells. Lacking amino acids. May contain stains and color indicators (EMB) Eosin-methylene blue agar (EMB) Contains methylene blue, toxic to Gram + bacteria, allowing only the growth of Gram – bacteria.
Why is selective media important?
Though selective media provide important information on those chemicals that prevent or hinder growth of an organism’s cells, they cannot provide much data on how the growth of those cells can vary based on different chemicals and environments.
What are the advantages of using selective media?
The advantage of using selective media is the ability to control what will and will not grow on a particular culture plate or petri dish. Selective media can include dyes and other chemicals such as antibiotic types, specifically neomycin, that prevent the growth of some types of cells.
Why use selective media and differential media?
Biologists use selective media along with differential media to isolate and identify different bacterial organisms. Both medium types operate differently. Selective media isolate organisms, and provide a growing environment conducive to some types of organisms but not to others. Differential media provide a growing environment that allows particular organisms to grow in different ways. As the name suggests, differential media differentiate between types of the same organism. Addressing the uses and applications of selective media requires you to compare and contrast it to differential media.
How does selective media affect cells?
As mentioned, selective media provide strong feedback on what chemicals can affect the growth of certain cells, and how those chemicals affect the cells. Although this provides important information on chemicals that have a negative effect, it is often more difficult to use selective media to isolate chemicals that might have a positive effect. If an organism’s cells continue to grow upon adding certain chemicals to a selective media, scientists often cannot determine whether that growth is caused by the chemical’s introduction, or if the growth is natural and unaffected by the chemical’s introduction.
What is differential media?
Differential media provide a growing environment that allows particular organisms to grow in different ways. As the name suggests, differential media differentiate between types of the same organism. Addressing the uses and applications of selective media requires you to compare and contrast it to differential media.
Is selective media an on/off switch?
In this way, selective media act as an on/off switch; either the cells grow, or they do not. Differential media, however, act as a dimmer; cells grow, but at different rates and in different ways. Consequently, when analyzing the growth and death factors of a certain organism’s cells, it is necessary to use selective and differential media. ...
Who is Samuel Hamilton?
His work has appeared in “The Penn,” “The Antithesis,” “New Growth Arts Review" and “Deek” magazine. Hamilton holds a Master of Arts in English education from the University of Pittsburgh, and a Master of Arts in composition from the University of Florida. Photo Credits.
What is selective media?
Selective and differential media are used to isolate or identify particularorganisms. Selective media allow certain types of organisms to grow, and inhibitthe growth of other organisms. The selectivity is accomplished in several ways.For example, organisms that can utilize a given sugar are easily screened bymaking that sugar the only carbon source in the medium. On the other hand,selective inhibition of some types of microorganisms can be achieved by addingdyes, antibiotics, salts or specific inhibitors which affect the metabolism orenzyme systems of the organisms. For example, media containing potassiumtellurite, sodium azide or thallium acetate (at concentrations of 0.1 - 0.5 g/l) willinhibit the growth of Gram-negative bacteria. Media supplemented with penicillin(5-50 units/ml) or crystal violet (2 mg/l) will inhibit the growth of Gram-positivebacteria. Tellurite agar, therefore, is used to select for Gram-positive organisms,and nutrient agar supplemented with penicillin can be used to select for Gram-negative organisms.
What is mannitol salt agar used for?
Mannitol salt agar is a selective medium used for the isolation of pathogenicstaphylococci. The medium contains mannitol, a phenol red indicator, and 7.5%sodium chloride. The high salt concentration inhibits the growth of most bacteriaother than staphylococci. On MSA, pathogenic Staphylococcus aureus producessmall colonies surrounded by yellow zones. The reason for this change in color isthat S. aureus ferments the mannitol, producing an acid, which, in turn, changesthe indicator from red to yellow. The growth of other types of bacteria is generallyinhibited.