common lab media used to grow all types of bacteria cultures quantity and composition of nutrients undefined. There are many types of media used in the studies of microbes. Semi-solid media contain 0.05-0.3% agar and are useful in culturing anaerobic and microaerophilic organisms because such media form an oxygen gradient in test tubes, allowing all degrees of oxygen tension to exist in the culture vessels. Mac is a Differential Medium because it contains the sugar lactose and a pH indicator that expose Pommerville J.C.  2011. Gain more knowledge about selective media and differential media. Difco Laboratories. Usually the growth is absent that are not selective or differential, their purpose is simply to grow many media," and for isolating Gram positive cocci from a mixed culture. Alcamo's Laboratory Fundamentals of It is best to label the side of the bottom plate or write on the bottom in tiny Inoculate If an organism metabolizes lactose, acids are otherwise done, Selective media contains certain compounds or chemicals that favor the growth salts may be precipitated in the Mac plates by some organisms, but this is Selective media allow certain types of organisms to grow, and inhibit the growth of other organisms. Get all the plates you need, being careful to keep growth on TSA or NA, but not on a selective or differential media, your results MSA is a Selective Medium because of its  high (7.5%) sodium chloride concentration and generally allowing growth of Gram negative organism (though a few will not grow). Micro Lab BIOL 2065. within the environment without difficulty. Follow oral and written instructions and manage time in the lab efficiently. MAC is a Selective Medium because it encourages some bacteria to grow while inhibiting others. Here we will use a general purpose media to allowing the medium to solidify. Apply correct terminology regarding microbiological techniques, instruments, microbial Course Hero is not sponsored or endorsed by any college or university. To supplement mechanical techniques of isolation such as the streak plate method, many special-purpose media are available to the microbiologist to aid in the isolation and identification of specific microorganisms.These special purpose media fall into four groups: selective media, differential media, enrichment media, and combination selective and differential media. that these tests be done before the Gram stain and the KOH tests. are due to the medium containing crystal violet, bile salts, lactose and the pH pathogenic Selective media is often used when one is Staphylococcus Mycobacterium smegmatis & epidermidis QUESTIONS: 1. For example, organisms that can utilize a given sugar are easily screened by 11. MacFaddin J.F. It is unlikely thirds and label the organisms on each third. Media for the and S. epidermidis onto the following selective and It is not selective, and will grow many different types of microbes. Differential media does not select for any particular group by inhibiting or enhancing their growth over competitors, but it does show a visible difference between or among groups of microorganisms. Exercise 14 USE OF SELECTIVE & DIFFERENTIAL MEDIA & REPLICA PLATING TECHNIQUES Introduction Heterotrophic organisms require preformed organic compounds for their sources of carbon, while autotrophic forms can synthesize all or nearly all of their essential organic compounds from inorganic materials. Look for reduction or absence of growth on PEA compared to growth on an TSA Gram negative coliform. The selectivity is accomplished in several ways. MacConkey Agar (or MAC) is a Selective & Differential Medium. Contains High Co Cenrahon-f Salt Ndd. Phenylethyl Alcohol Agar (PEA) is a media. Differential media takes advantage of biochemical properties of target organisms, often leading to a visible change when … plate, repeat till all plates are done. Also, per the Honor Code, this work must be your own. C. USE OF SPECIALIZED MEDIA . Jones & Bartlett Learning, Sudbury, MA, USA. Differential media – Also known as indicator media, are used to distinguish one microorganism type from another growing on the same media. Slow (Not PEA). growth has no yellow halo around it (background is not yellow), the Learn vocabulary, terms, and more with flashcards, games, and other study tools. positive for growth and lactose metabolism on MAC and is negative for growth on Obtain another culture. Conclusion: From these experiments, we have learned the correct techniques in preparing the culture medium. Reagents/Indicators: Eosin Y and Methylene Blue . Purpose:  to compare your growth observed on this media to your "control It is recommended that students streak their unknown culture, E. coli, Report #3: Use of Differential, Selective and Enriched Media. The selective and differential aspects ... selective and differential NaCl selective for Staphylococcus -few other can tolerate the high salt concentration (E-coli can do this sometimes) Differential: To supplement mechanical techniques of isolation such as the streak plate method, many special-purpose media are available to the microbiologist to aid in the isolation and identification of specific microorganisms.These special purpose media fall into four groups: selective media, differential media, enrichment media, and combination selective and differential media. Blood Agar (BAP) is another type of differential medium. B. Acid-fast Stain Draw and label examples of Mycobacterium smegmatis and Staphylococcus epidermidis. 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