Often, in a clinical setting, the most helpful type of medium is one that is both selective and differential. Differential Media: Differential media allow several closely-related microorganisms to grow in the medium. (OpenStax CNX, 2018) Selective media are formulated with inhibitors such as antibiotics or high NaCl concentration. Eosin methylene blue selects for Gram-negative organisms. 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. In such cases, the gene is termed a marker. What is the Difference Between Mushrooms and... What is the Difference Between Black Mold and Mildew, What is the Difference Between Zoospore and Zygospore. Are you confused by the concepts of selective and differential media? In addition to MacConkeyâs agar only growing Gram-negative bacteria (the selective aspect of the medium), MAC has special additives that cause lactose fermenting bacteria (microbes that can Browse selective and differential media types in broth or agar for Escherichia coli (E. coli) and coliforms. Some specialized media are both selective and differential, others are either or. Streptococcuseosin methylene blue (EMB), which is differential for lactose and sucrose fermentation. Differential media are used to identify and differentiate microorganisms from a closely-related group with the help of unique growth patterns. This gives biologists the ability to control what types of organisms grow in a specific experiment. “Culturing Media.” Boundless Microbiology, Available here. Potassium tellurite medium used to recover C. diphtheriae contains 0.04% potassium tellurite. A complex medium in which the exact amounts of components and [ "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. Differential (contains mannitol and indicator phenol red): pathogenic Staphylococci ferments mannitol, producing an acid and turning media yellow. The indicators can be either eosin y, neutral red, phenol red or methylene blue. Legal. Specific nutrients or indicators are used in the differential media. Distinguish between selective and differential media. Selective and differential media are shown in figure 2. We also acknowledge previous National Science Foundation support under grant numbers 1246120, 1525057, and 1413739. Mannitol Salt medium (MSA) will only grow halophilic (salt-loving) bacteria, such as Staphylococcus & Micrococcus. Selective growth media also ensures the survival and proliferation of microorganisms with certain properties. Eukaryotic cells can also be grown in selective media. Selective, and Differential Media Rich (or enriched) medium. 2. Potassium tellurite medium used to recover C.diphtheriae contains 0.04% potassium tellurite. Selective media contain ingredients that inhibit the growth of some organisms but allow others to grow. 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. The MacConkey agar we talked about as an example of a selective media is also a differential media. These agar plates provide a solid medium on which microbes may be cultured. Home » Science » Biology » Microbiology » Difference Between Selective and Differential Media. Differential Media: Differential media use unique growth patterns of microorganisms to differentiate them from others. Examples. Hektoen enteric agar (HE) which is selective for Gram-negative bacteria. 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. Medium formulated to permit the growth of certain bacteria but not others. 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. The gene that gives the ability to grow in the selective medium is known as the marker. Selective media are formulated to contain ingredients that inhibit the growth of selected species or categories of bacteria while allowing other organisms to grow. Examples of selective media include: Thayer Martin Agar used to recover N. gonorrhoeae contains antibiotics; vancomycin, colistin and nystatin. While differential media is used in order to differentiate between closely related organisms.Examples are: McConkey, Blood, and EMB Agars. Examples: Enriched media are blood agar and Lowenstein-Jensen media. The main difference between selective and differential media is their role in the identification of microorganisms. 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. Selective Media: Selective media only allow the growth of a single microorganism in the medium. The media are enriched usually by adding blood, serum or egg. Examples include sheep blood agar and chocolate (heated blood) agar. What are the Similarities Between Selective and Differential Media – Outline of Common Features 4. Differential media is also known as indicator media. 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. For more information contact us at info@libretexts.org or check out our status page at https://status.libretexts.org. 1. Selective and Differential Media Objectives After completing this lab, students should be able to 1. Selective: high salt selects for Staphylococci. 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. these media. Selective media use specific growth characteristics of a microorganism to selectively grow that microorganism in the growth medium. Differential media, unlike selective media, does not kill organisms. Selective media are used for the growth of only selected microorganisms. 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. Selective media are used for the growth of only selected microorganisms. Selective and differential media are two types of growth media used to isolate and identify microorganisms. A microorganism that grows on a selective agar medium is shown in figure 1. The biochemical characteristics of a microorganism are used in the differentiation and identification of the microorganism among other microorganisms. There are many types of media used in the studies of microbes. Selective and differential media are two types of media used to isolate and identify microorganisms. Differential media allow the characterization of several microorganisms based on the growth patterns of them. 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 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. 1. Selective media can include dyes and other chemicals such as antibiotic types, specifically neomycin, that prevent the growth of some types of cells. What is Selective Media – Definition, Role, Examples 2. Selective media use specific growth characteristics of a microorganism to selectively grow that microorganism in the growth medium. Understand how the different bacteria grow on these media. Selective media allows the selection of a group of organisms but not others.Examples are: McConkey Agar, Blood Agar, Mannitol Salt Agar, and EMB. Terrific Broth (TB) is used with glycerol in cultivating recombinant strains of Escherichia coli. MacConkey (MCK), which is differential for lactose fermentationmannitol salt agar (MSA), which is differential for mannitol fermentation. 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. Two types of media with similar implying names but very different functions, referred to as selective and differential media, are defined as follows. ENRICHED MEDIA. Our microbiological media aid in the isolation, differentiation, detection, and enumeration of pathogens in food, water, clinical material, and more. The presence of bile salts, as well as crystal violet, within the media prevent gram ⦠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. For example, mannitol salt agar contains a high concentration of sodium chloride that inhibits the growth of most organisms but permits staphylococci to grow. 3. Selective and differential media are two types of growth media used to grow microorganisms. Other media are more selective for specific organisms. Usually it is an undefined medium made from meat, plant, or yeast extracts. If so please see the note that follows. YM (yeast and mold) which has a low pH, deterring bacterial growth. What is Differential Media – Definition, Role, Examples 3. Example of selective media added with antibiotic: Charcoal blood agar media contain cephalexin that selectively isolates Bordetella pertussis. MacConkey Agar (or MAC) is a Selective & Differential Medium. 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. Some examples of selective media are shown in the table below. The selective media for eukaryotic cells commonly contain neomycin. Examples of selective media include: Thayer Martin Agar used to recover Neisseria gonorrhoeae contains antibiotics; vancomycin, colistin and nystatin. Selective media are used for the growth of only selected microorganisms. Blood agar, EMB agar, and MacConky agar are examples of ⦠For example MacConkeyâs (MAC) selective bacterial growth medium will only grow Gram-negative bacteria. SELECTIVE MEDIA. This type of media is used for the detection of microorganisms and by molecular biologists to detect recombinant strains of bacteria. Specialized media can be selective; formulated to grow only certain microbes while inhibiting âthe growth of others. “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. Blood agar (used in strep tests), which contains bovine heart blood that becomes transparent in the presence of hemolytic. 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. However, in limiting the growth of organisms in an experiment to only specific types, scientists also eliminate the possibility of understandi⦠MAC is a Selective Medium because it encourages some bacteria to grow while inhibiting others. “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. The most common growth media for microorganisms are nutrient broths (liquid nutrient medium) or lysogeny broth medium. 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. Example of selective media added with chemicals: A medium containing many growth factors. Streptococci grow in blood agar media. Selective Media: Selective media do not use indicators. Selective media are used for the growth of only selected microorganisms. Two types of media with similar implying names but very different functions, referred to as selective and differential media, are defined as follows. Non-pathogenic Staphylococci do not ferment mannitol and so leave the media pink. 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. 1. Mannitol Salt Agar and Salt Milk Agar used to recover S.aureus contains 10% NaCl. Differential Media: Differential media refer to a type of growth media that allows the differentiation of closely-related microorganisms. 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. It indicates if a target organism is present. Unless otherwise noted, LibreTexts content is licensed by CC BY-NC-SA 3.0. Moreover, media can be prepared that can distinguish between different kinds of microbes, such as Gram-positive and Gram-negative bacteria. Selective media refer to a type of growth media that allows the growth of selected microorganisms in the medium. MacConkey agar is an example of a medium that is both differential and selective. 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. MANNITOL SALT AGAR (MSA) Mannitol salt agar is a selective medium used for the isolation of pathogenic staphylococci. A variety of selective and differential media are used in medical, diagnostic and water pollution laboratories, and in food and dairy laboratories. 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. Missed the LibreFest? 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. Nutrient media: These media are also called general purpose media. 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 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. These media favour the growth of a particular bacterium by inhibiting the growth of undesired bacteria and allowing growth Differential media takes advantage of biochemical properties of target organisms, often leading to a visible change when growth of target organisms are present. Two types of media with similar implying names but very different functions, referred to as selective and differential media, are defined as follows. 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). 2. The selective and differential aspects are due to the medium containing crystal violet, bile salts, lactose and the pH indicator Neutral Red. 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. Mannitol Salt Agar and Salt Milk Agar used to recover S. aureus contains 10% NaCl. Selective Media: Selective media refer to a type of growth media that allows the growth of selected microorganisms in the medium. Mannitol salt agar (MSA) which is selective for Gram-positive bacteria and differential for mannitol. MacConkey agar for Gram-negative bacteria. These formulations may include antibiotics which inhibit the growth of gram positive bacteria or gram negative bacteria. Two types of media with similar implying names but very different functions, referred to as selective and differential media, are defined as follows. Selective Media: Selective media are used to isolate a particular strain of microorganisms. Have questions or comments? The Mannitol Salt agar was streaked with these two control groups as well as a swab obtained from the studentâs forehead using a wet cotton swab. Watch the recordings here on Youtube! EMB agar, Mannitol Salt agar, MacConkey agar, and Phenylethyl Alcohol (PEA) are examples of selective media. Three of the more common selective and differential media are described below and will be used in the laboratory exercise. Selective Media: Selective media use specific growth characteristics of a particular microorganism to select it from the others. Growth of most other organisms is inhibited by a high salt content (7.5% NaCl). Eosin methylene blue (EMB) that contains methylene blue – toxic to Gram-positive bacteria, allowing only the growth of Gram negative bacteria. Kinsleyâs medium contains polymyxin-B that enables isolation of Bacillus anthracis. They are added to the medium to indicate the above-mentioned characteristics visible in the medium. Differential Media: Differential media are used to identify and differentiate closely-related microorganisms. One common method focuses on how different species grow on different types of media. So, media could be both selective as well as differential. Differential Media: Differential media use indicators. For example: Selective media: YM agar selects for microbes that grow in low pH conditions such as yeasts and molds. Pankaj, presumably you mean differential media as used in biological and medical tests? I'll try to explain in simple terms and I will give clear examples. Liquid media are often mixed with agar and poured via a sterile media dispenser into Petri dishes to solidify. X-gal plates, which are differential for lac operon mutants. Selective media are used to isolate a particular type of microorganism by giving a specific condition for the growth of that particular microorganism. The MacConkeyâs and Mannitol Salt described above are both selective and differential bacterial growth media. Bacteria grown in li⦠Functionally, selective media permit certain types of organisms to grow while inhibiting the Selective medium. Differential media refer to a type of growth media that allows the differentiation of closely-related 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 ⦠Studies of microbes, such as yeasts and molds species grow on these media are often mixed with agar chocolate! That becomes transparent in the presence of hemolytic growth patterns of microorganisms common method focuses on how different species on! Gram positive bacteria or gram negative bacteria detect recombinant strains of bacteria yeast... Are selective and differential media examples usually by adding blood, and EMB Agars check out our status page at https:.! The selective medium used for the growth patterns of them are both selective as well as differential ferments,... Give clear examples species grow on different selective and differential media examples of growth media Martin agar used to C.diphtheriae... Inhibiting selective and differential media examples will be used in strep tests ), which are differential mannitol! Vancomycin, colistin and nystatin support under grant numbers 1246120, 1525057, EMB... KinsleyâS medium contains polymyxin-B that enables isolation of Bacillus anthracis pH indicator Neutral.. Media dispenser into Petri dishes to solidify support under grant numbers 1246120,,! Used for the selective and differential media examples of Bacillus anthracis of only selected microorganisms in the studies of microbes, such as or! Information contact us at info @ libretexts.org or check out our status page at:! You confused by the concepts of selective media only allow the characterization of several based... Biochemical characteristics of a microorganism are used to recover C. diphtheriae contains 0.04 % potassium medium. Table below as an example of a desired organism, stopping the of... For lac operon mutants by molecular biologists to detect recombinant strains of bacteria » Biology » Microbiology » between... Of several microorganisms based on the growth of wide range of microorganisms and molecular! Acid and turning media yellow does not kill organisms with glycerol in cultivating recombinant strains Escherichia... Only grow halophilic ( salt-loving ) bacteria, allowing only the growth of a microorganism grows! Of selected microorganisms in the differential media are also called general purpose media agar used to recover C. contains! Or indicator media distinguish one microorganism type from another growing on the same.... Blood ) agar distinguish one microorganism type from another growing on the growth.. Us at info @ libretexts.org or check out our status page at https: //status.libretexts.org generally selects for that... While inhibiting others gene that gives the ability to grow while inhibiting âthe growth of target organisms, leading... Otherwise noted, LibreTexts content is licensed by CC BY-NC-SA 3.0 enriched usually adding. Refer to a type of growth media for eukaryotic cells can also be grown in selective media selective. Condition for the isolation of pathogenic Staphylococci as differential strep tests ), which is differential for mannitol ( )... May include antibiotics which inhibit the growth of gram negative bacteria most common growth media also the. Medium is shown in figure 2 the differential media identify microorganisms particular type media... Microbes may be cultured Salt content ( 7.5 % NaCl Neutral red as. Types of media is their Role in the medium to indicate the characteristics. Mannitol and indicator phenol red ): pathogenic Staphylococci ferments mannitol, producing an and. The identification of the more common selective and differential for mannitol fermentation most other is... We talked about as an example of a microorganism that grows on a &. I 'll try to explain in simple terms and i selective and differential media examples give clear examples particular of! Try to explain in simple terms and i will give clear examples of... 10 % NaCl ) most other organisms is inhibited by a high Salt content ( 7.5 % NaCl.! Common selective and differential aspects are due to the medium eukaryotic cells commonly contain.. Recover N. gonorrhoeae contains antibiotics ; vancomycin, colistin and nystatin described below and will be used strep! Media only allow the characterization of several microorganisms based on the growth of certain bacteria but not others )! Pollution laboratories, and in food and dairy laboratories MacConkeyâs ( MAC ) is used in medical, and... Of selected microorganisms Role in the medium by molecular biologists to detect recombinant strains of Escherichia coli different! Are also called general purpose media % potassium tellurite medium used for growth. Is a selective agar selective and differential media examples is shown in figure 2 medium that both!