These formulations may include antibiotics which inhibit the growth of gram positive bacteria or gram negative bacteria. Differential (contains mannitol and indicator phenol red): pathogenic Staphylococci ferments mannitol, producing an acid and turning media yellow. Gancyclovir is an exception to the rule as it is used to specifically kill cells that carry its respective marker, the Herpes simplex virus thymidine kinase (HSV TK). Mannitol Salt Agar and Salt Milk Agar used to recover S.aureus contains 10% NaCl. Example of selective media added with antibiotic: Charcoal blood agar media contain cephalexin that selectively isolates Bordetella pertussis. If so please see the note that follows. Example of selective media added with chemicals: Selective Media: Selective media are used to isolate a particular strain of microorganisms. What is Selective Media       – Definition, Role, Examples 2. (OpenStax CNX, 2018) Selective media are formulated with inhibitors such as antibiotics or high NaCl concentration. Specialized media can be selective; formulated to grow only certain microbes while inhibiting ​the growth of others. Specific nutrients or indicators are used in the differential media. This gives biologists the ability to control what types of organisms grow in a specific experiment. In addition to MacConkey’s agar only growing Gram-negative bacteria (the selective aspect of the medium), MAC has special additives that cause lactose fermenting bacteria (microbes that can 2. Some examples of selective media are shown in the table below. This type of media uses the biochemical characteristics of a microorganism growing in the presence of specific nutrients or indicators (such as neutral red, phenol red, eosin y, or methylene blue) added to the medium to visibly indicate the defining characteristics of a microorganism. Missed the LibreFest? Distinguish between selective and differential media. Figure 2: Selective (right) and Differential (left) Media, Contains bovine heart blood that becomes transparent in the presence of hemolytic, Differential for lactose and sucrose fermentation. Medium formulated to permit the growth of certain bacteria but not others. Selective and differential media are two types of growth media used to isolate and identify microorganisms. Selective medium. Eukaryotic cells can also be grown in selective media. Other media are more selective for specific organisms. What is the Difference Between Streak Plate and Pour... What is the Difference Between Asteroid and Meteorite, What is the Difference Between Seltzer and Club Soda, What is the Difference Between Soda Water and Sparkling Water, What is the Difference Between Corduroy and Velvet, What is the Difference Between Confidence and Cocky, What is the Difference Between Silk and Satin. These media favour the growth of a particular bacterium by inhibiting the growth of undesired bacteria and allowing growth Selective and differential media are shown in figure 2. A variety of selective and differential media are used in medical, diagnostic and water pollution laboratories, and in food and dairy laboratories. Potassium tellurite medium used to recover C. diphtheriae contains 0.04% potassium tellurite. Selective growth media also ensures the survival and proliferation of microorganisms with certain properties. Examples: Enriched media are blood agar and Lowenstein-Jensen media. Selective media are used for the growth of only selected microorganisms. The main difference between selective and differential media is their role in the identification of microorganisms. Differential Media: Differential media use indicators. Differential media are used to identify and differentiate microorganisms from a closely-related group with the help of unique growth patterns. While these are just a few examples of how types of media can help microbiologists distinguish between microbes, there are many other types of selective and differential media. Hektoen enteric agar (HE) which is selective for Gram-negative bacteria. Selective: high salt selects for Staphylococci. The Mannitol Salt agar was streaked with these two control groups as well as a swab obtained from the student’s forehead using a wet cotton swab. The gene that gives the ability to grow in the selective medium is known as the marker. EMB agar, Mannitol Salt agar, MacConkey agar, and Phenylethyl Alcohol (PEA) are examples of selective media. MANNITOL SALT AGAR (MSA) Mannitol salt agar is a selective medium used for the isolation of pathogenic staphylococci. MacConkey (MCK), which is differential for lactose fermentationmannitol salt agar (MSA), which is differential for mannitol fermentation. 3. Eosin methylene blue (EMB) that contains methylene blue – toxic to Gram-positive bacteria, allowing only the growth of Gram negative bacteria. Differential media, unlike selective media, does not kill organisms. 1. Examples. The biochemical characteristics of a microorganism are used in the differentiation and identification of the microorganism among other microorganisms. What is the Difference Between Mushrooms and... What is the Difference Between Black Mold and Mildew, What is the Difference Between Zoospore and Zygospore. Some specialized media are both selective and differential, others are either or. Mannitol salt agar (MSA) which is selective for Gram-positive bacteria and differential for mannitol. Selective growth media are also used in cell culture to ensure the survival or proliferation of cells with certain properties, such as antibiotic resistance or the ability to synthesize a certain metabolite. These agar plates provide a solid medium on which microbes may be cultured. 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. Selective growth media for eukaryotic cells commonly contain neomycin to select cells that have been successfully transfected with a plasmid carrying the neomycin resistance gene as a marker. Some Examples of Selective and Differential Media: Mannitol Salt Agar (MSA) Mannitol Salt Agar (MSA) is a selective medium for the isolation of pathogenic and non-pathogenic Staphylococci. Media lacking an amino acid such as proline in conjunction with E. coli unable to synthesize it were commonly used by geneticists before the emergence of genomics to map bacterial chromosomes. Differential media is also known as indicator media. Xylose lysine desoxyscholate (XLD), which is selective for Gram-negative bacteria buffered charcoal yeast extract agar, which is selective for certain gram-negative bacteria, especially Legionella pneumophila. USE OF SELECTIVE AND DIFFERENTIAL MEDIA Overview Samples obtained from nature are most often a mix of many types of microorganisms, which can be identified or isolated by several methods. Selective Media: Selective media use specific growth characteristics of a particular microorganism to select it from the others. Bacteria grown in li… these media. Two types of media with similar implying names but very different functions, referred to as selective and differential media, are defined as follows. Have questions or comments? The selective media for eukaryotic cells commonly contain neomycin. YM (yeast and mold) which has a low pH, deterring bacterial growth. However, in limiting the growth of organisms in an experiment to only specific types, scientists also eliminate the possibility of understandi… Media that inhibit the growth of unwanted microorganisms and support the growth of the organism of interest by supplying nutrients and reducing competition are called selective media. Mannitol Salt Agar and Salt Milk Agar used to recover S. aureus contains 10% NaCl. Differential Media: Differential media allow several closely-related microorganisms to grow in the medium. Growth of most other organisms is inhibited by a high salt content (7.5% NaCl). Selective and differential media is extremely useful when examining mixed bacterial cultures since it provides: a simple way to "screen out" certain bacterial species some biochemical information on the organisms present in the culture (presumptive identification) Media can be Selective and Differential MacConkey agar for Gram-negative bacteria. Some examples of selective media include: Differential media or indicator media distinguish one microorganism type from another growing on the same media. Examples of selective media include: Thayer Martin Agar used to recover Neisseria gonorrhoeae contains antibiotics; vancomycin, colistin and nystatin. Selective and differential media are two types of growth media used to grow microorganisms. Differential Media: Differential media use unique growth patterns of microorganisms to differentiate them from others. Home » Science » Biology » Microbiology » Difference Between Selective and Differential Media. Selective Media: Selective media do not use indicators. Selective media inhibit the growth of certain bacteria and allow for the growth of others.This permits the isolation of desired bacteria in pure subcultures.An example of a selective media is Coulmbia CNA Agar which contains two antibiotics: Colistin and Nalidixic acid to inhibit Gram negative bacteria, leaving only the GRAM POSITIVES to grow. Selective media are used for the growth of only selected microorganisms. The selective and differential aspects are due to the medium containing crystal violet, bile salts, lactose and the pH indicator Neutral Red. Mannitol Salt medium (MSA) will only grow halophilic (salt-loving) bacteria, such as Staphylococcus & Micrococcus. For example MacConkey’s (MAC) selective bacterial growth medium will only grow Gram-negative bacteria. Blood agar, EMB agar, and MacConky agar are examples of … Two types of media with similar implying names but very different functions, referred to as selective and differential media, are defined as follows. Are you confused by the concepts of selective and differential media? 1. Selective media refer to a type of growth media that allows the growth of selected microorganisms in the medium. For example, if a particular microorganism is resistant to a particular antibiotic such as tetracycline or ampicillin, that antibiotic can be added to the medium, prohibiting the growth of other microorganisms in that medium. 2. An example of differential/selective media used in this experiment was Mannitol Salt agar used to isolated the bacterium Staphylococcus aureus and Staphylococcus epidermidis. Browse selective and differential media types in broth or agar for Escherichia coli (E. coli) and coliforms. Moreover, media can be prepared that can distinguish between different kinds of microbes, such as Gram-positive and Gram-negative bacteria. A microorganism that grows on a selective agar medium is shown in figure 1. Differential Media: Differential media refer to a type of growth media that allows the differentiation of closely-related microorganisms. There are many types of media used in the studies of microbes. Functionally, selective media permit certain types of organisms to grow while inhibiting the Selective Media: Selective media refer to a type of growth media that allows the growth of selected microorganisms in the medium. [ "article:topic", "Selective Media", "Differential media", "authorname:boundless", "showtoc:no", "license:ccbysa" ], https://bio.libretexts.org/@app/auth/2/login?returnto=https%3A%2F%2Fbio.libretexts.org%2FBookshelves%2FMicrobiology%2FBook%253A_Microbiology_(Boundless)%2F6%253A_Culturing_Microorganisms%2F6.3%253A_Culturing_Bacteria%2F6.3C%253A_Selective_and_Differential_Media, 6.3D: Aseptic Technique, Dilution, Streaking, and Spread Plates. The media are enriched usually by adding blood, serum or egg. The most common growth media for microorganisms are nutrient broths (liquid nutrient medium) or lysogeny broth medium. Streptococcuseosin methylene blue (EMB), which is differential for lactose and sucrose fermentation. This type of media is used for the detection of microorganisms and by molecular biologists to detect recombinant strains of bacteria. What is the Difference Between Selective and Differential Media      – Comparison of Key Differences, Key Terms: Antibiotic Resistance, Biochemical Characteristics, Differential Media, Indicators, Marker, Microorganisms, Selective Media. Selective media generally selects for the growth of a desired organism, stopping the growth of or altogether killing non-desired organisms. A selective media only permits the development of particular organisms, while a differential media discerns one species of the organism from the other growing on the similar substrate. They are added to the medium to indicate the above-mentioned characteristics visible in the medium. Two types of media with similar implying names but very different functions, referred to as selective and differential media, are defined as follows. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Pankaj, presumably you mean differential media as used in biological and medical tests? Growth pattern : Different microorganisms show different growth patterns in the selective as well as differential media, which can be characterized by the size, shape, texture, colour and other notable features. Selective Media: Selective media only allow the growth of a single microorganism in the medium. Selective media use specific growth characteristics of a microorganism to selectively grow that microorganism in the growth medium. Selective media are used for the growth of only selected microorganisms. Selective and Differential Media Objectives After completing this lab, students should be able to 1. The MacConkey agar we talked about as an example of a selective media is also a differential 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. Legal. These media are non selective and they contain general nutrients which required for the growth of wide range of microorganisms. The MacConkey’s and Mannitol Salt described above are both selective and differential bacterial growth media. Blood agar (used in strep tests), which contains bovine heart blood that becomes transparent in the presence of hemolytic. Selective media can include dyes and other chemicals such as antibiotic types, specifically neomycin, that prevent the growth of some types of cells. Selective media are formulated to contain ingredients that inhibit the growth of selected species or categories of bacteria while allowing other organisms to grow. Differential Media: Differential media are used to identify and differentiate closely-related microorganisms. Differential media takes advantage of biochemical properties of target organisms, often leading to a visible change when growth of target organisms are present. The indicators can be either eosin y, neutral red, phenol red or methylene blue. Selective media contain ingredients that inhibit the growth of some organisms but allow others to grow. 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 … Watch the recordings here on Youtube! For example: Selective media: YM agar selects for microbes that grow in low pH conditions such as yeasts and molds. While differential media is used in order to differentiate between closely related organisms.Examples are: McConkey, Blood, and EMB Agars. Terrific Broth (TB) is used with glycerol in cultivating recombinant strains of Escherichia coli. Undefined medium. ENRICHED MEDIA. I'll try to explain in simple terms and I will give clear examples. X-gal plates, which are differential for lac operon mutants. Examples of selective media include: Thayer Martin Agar used to recover N. gonorrhoeae contains antibiotics; vancomycin, colistin and nystatin. Examples of differential media include: The LibreTexts libraries are Powered by MindTouch® and are supported by the Department of Education Open Textbook Pilot Project, the UC Davis Office of the Provost, the UC Davis Library, the California State University Affordable Learning Solutions Program, and Merlot. In such cases, the gene is termed a marker. Both selective and differential media are used to isolate and identify microorganisms. Potassium tellurite medium used to recover C.diphtheriae contains 0.04% potassium tellurite. Normally, the presence of a specific gene or an allele of a gene confers upon the cell the ability to grow in the selective medium. So, media could be both selective as well as differential. Some differential media are also selective, for example, standard enteric agars such as MacConkey and EMB agars, which are selective for gram-negative coliforms and can differentiate lactose-fermenting and non-lactose-fermenting bacteria. Three of the more common selective and differential media are described below and will be used in the laboratory exercise. Selective media allows the selection of a group of organisms but not others.Examples are: McConkey Agar, Blood Agar, Mannitol Salt Agar, and EMB. Unless otherwise noted, LibreTexts content is licensed by CC BY-NC-SA 3.0. 1. “Neisseria gonorrhoeae 01” (Public Domain) via Commons Wikimedia, Lakna, a graduate in Molecular Biology & Biochemistry, is a Molecular Biologist and has a broad and keen interest in the discovery of nature related things, Difference Between Selective and Differential Media, What are the Similarities Between Selective and Differential Media, What is the Difference Between Selective and Differential Media, What is the Difference Between E coli and Salmonella. “Trichophyton tonsurans on Dermatophyte Selective Agar” By Nathan Reading from Halesowen, UK – Trichophyton tonsurans on Dermatophyte Selective Agar (CC BY 2.0) via Commons Wikimedia 2. Liquid media are often mixed with agar and poured via a sterile media dispenser into Petri dishes to solidify. Selective media are used for the growth of only selected microorganisms. What are the Similarities Between Selective and Differential Media      – Outline of Common Features 4. They remain solid, as very few bacteria are able to decompose agar (the exception being some species in the genera: Cytophaga, Flavobacterium, Bacillus, Pseudomonas, and Alcaligenes). Two types of media with similar implying names but very different functions, referred to as selective and differential media, are defined as follows. The presence of bile salts, as well as crystal violet, within the media prevent gram … Eosin methylene blue selects for Gram-negative organisms. Selective media use specific growth characteristics of a microorganism to selectively grow that microorganism in the growth medium. It indicates if a target organism is present. A complex medium in which the exact amounts of components and Usually it is an undefined medium made from meat, plant, or yeast extracts. Differential media refer to a type of growth media that allows the differentiation of closely-related microorganisms. Streptococci grow in blood agar media. Selective media are used to isolate a particular type of microorganism by giving a specific condition for the growth of that particular microorganism. For example, mannitol salt agar contains a high concentration of sodium chloride that inhibits the growth of most organisms but permits staphylococci to grow. Selective and differential media are two types of media used to isolate and identify microorganisms. Non-pathogenic Staphylococci do not ferment mannitol and so leave the media pink. The main difference between selective and differential media is that selective media are used to isolate a particular strain of microorganisms whereas differential media are used to identify and differentiate a closely-related group of microorganisms. Kinsley’s medium contains polymyxin-B that enables isolation of Bacillus anthracis. A medium containing many growth factors. Selective, and Differential Media Rich (or enriched) medium. MacConkey agar is an example of a medium that is both differential and selective. MacConkey Agar (or MAC) is a Selective & Differential Medium. The main difference between selective and differential media is that selective media are used to isolate a particular strain of microorganisms whereas differential media are used to identify and differentiate a closely-related group of microorganisms. What is Differential Media      – Definition, Role, Examples 3. Differential media allow the characterization of several microorganisms based on the growth patterns of them. Our microbiological media aid in the isolation, differentiation, detection, and enumeration of pathogens in food, water, clinical material, and more. Examples include sheep blood agar and chocolate (heated blood) agar. One common method focuses on how different species grow on different types of media. 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