Web. colorless above pH 6.8 and pink below pH 6.8). likely Gram negative, but this has to be confirmed with a Gram stain, as a few
(but not all of them). Now reflame your loop (important!) inhibiting the growth of Gram positive cells. Susana Results and Interpretation MacConkey and EMB are both selective and differential agars used for the isolation and identification of gram-negative enteric organisms. in Molecular and Applied Microbiology, and PhD in Applied Microbiology. II. Lab Report #3. Slow
Purpose Media
2. between a coliform and a noncoliform is simply whether the enteric can
is a Selective and Differential Medium that favors the growth of salt loving organisms (halophiles). for the inhibition of unwanted microorganisms. If growth is reduced or absent on PEA, then you most likely
because phenylethyl alcohol is in the medium and inhibits the growth of most Gram negative
Crystal
Difco Manual, 11th ed. 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 selection by PEA is often incomplete. Phenylethyl Alcohol is a Selective Medium. most organisms. of your "control
As some organisms inhibit or grow faster than others, using
Medium because of the presence of the sugar mannitol and the pH
Strong fermenters of sucrose or lactose will produce large amounts of acid, turning the microorganisms dark purple or black. The selectivity of the medium can be achieved by employing several methods and by adding certain inhibitors to the medium. Difco Laboratories. of fully inhibited), and Pseudomonas aeruginosa (Gram negative) is not
It is recommended
-purpose: widely-used culture medium which is both selective and differential. Then streak out the
Hence, selective media contain antimicrobials, dyes, alcohols, etc. that inhibits the growth of
General Microbiology I: BIO 203 604. MANNITOL SALT AGAR (MSA) Mannitol salt agar is a selective medium used for the isolation of pathogenic staphylococci. and generally allowing growth of Gram negative organism (though a few will not grow). Handbook of Microbiological Media, 2nd ed. Selective media generally selects for the growth of a desired organism, stopping the growth of or altogether killing non-desired organisms. Differential media are the culture media designed to distinguish microorganisms from one another by visible growth characteristics. Selective and Differential Media Varisce Alston March 28,2012 Dr. Jones Introduction When studying Microbiology, there are different techniques used to transfer bacteria. Inoculate one third with your unknown using a single quick streak. Figure 01: Methicillin-resistant Staphylococcus aureus selective medium. Em (PA). generally not used to identify species. Gram negative coliform. well on PEA, it probably is a Gram positive species.
that these tests be done before the Gram stain and the KOH tests. Obtain another culture. Key Points. Isolation-Cultivation-Identification-Maintenance of Medical Bacteria. 1998. DIFFERENTIAL STAINS A. Gram Stain B. Acid-fast Stain A. Gram Stain The previous lab introduced simple staining techniques that enable microbiologists to observe the morphological characteristics of bacteria. the streak. are most likely valid. Growing microbes is feasible only if they are provided with a suitable culture medium and other optimal growth conditions such as pH, and temperature. Summary. Overview and Key Difference Mac is a Differential Medium because it contains the sugar lactose and a pH indicator that expose
Introduction. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Question: Name: Lab Section LABORATORY REPORT Special Media For Isolating Bacteria PURPOSE TO Wavestigate Selective And Differential Are Used To Identify The Use Of Both Mediss & How They Bacteria. Start studying Lab Exercise 12: Special Media for Isolating Bacteria. Many different types of media are used to culture microorganisms. If an organism metabolizes lactose, acids are
2. metabolize lactose. Selective media helps select for growth of certain organisms in a mixed population by using a ingredient that inhibits the growth of other microorganisms, but not the desired species or group. Experimental rationale: Selective media can completely inhibit and/or slowly down the growth of certain species of bacteria. desired, S. saprophiticus may be used instead. It is not selective, and will grow many different types of microbes. Mannitol Salt Agar (MSA) plate. Let us say
You will need to compare this growth to growth on a
The selective and differential aspects
also differentiates b/w lactose-fermenting coliforms and lactose non-fermenters, which include potential pathogens such as … Please download PDF version here Difference Between Selective and Differential Media. indicator Phenol Red. If an organism ferments mannitol, an acid will be produced turning the indicator
Alcamo's Laboratory Fundamentals of
Selective and Differential Media 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. culture. Incubate your plates upside down in the incubator at 35-37 C for 1-2 days. If you keep the loop sterile, there is no need to reflame it! The Eosin and Methyl Blue in EMB inhibit the growth of Gram-positive bacteria. A culture medium is defined as a solid or liquid preparation which includes the necessary ingredients and conditions to grow, transport and store microorganisms. among the enterics. are due to the medium containing crystal violet, bile salts, lactose and the pH
thirds and label the organisms on each third. Specific inhibitors also can be included into media at various concentrations to suppress the growth of nonspecific microorganisms. differences between species. control TSA or NA plate. Selective media allow the growth of a specific type of microorganisms and inhibit the rest of the other microorganisms. Look for presence or absence of growth and if there is growth if the growth
not just inhibited a little. It is Selective
MSA. For example, if a particular microbe has the ability to utilize a specific sugar type, a selective medium for that particular microbe can be prepared by making that specific sugar type as the only carbon source available in the medium. Purpose: to compare your growth observed on this "control
They are designed in such a way that the medium composition supports only one type of microorganism and inhibits the growth of all other types of microorganisms. Press, Boca Raton, FL, USA. or NA plate. types of bacteria cheaply. Learn vocabulary, terms, and more with flashcards, games, and other study tools. enteric noncoliforms. Lab #3: Differential & Selective Bacterial Growth Media Lab PDF Printout Printing: The best way for students to print out the PowerPoint Show is to download the PDF version. and differential media. HYPOTHESES 1. MSA
These plates are used for distinguishing
TSA (Trypticase Soy Agar) and NA (Nutrient Agar) are General
Selective media and differential media are two important and commonly used media types among them. Selective media and differential media are two types of growth media. Makinji ㅏ Seleclive Or Gram-positivé Buelevia 2. Staphylococcus aureus ferments
3. EMB agar, Mannitol Salt agar, MacConkey agar, and Phenylethyl Alcohol (PEA) agar are several routinely used selective media in laboratories. inhibited partially, a number of Gram negatives are partially inhibited (instead
Media are included with necessary nutrients for the growth of microorganisms. enteric coliforms (diarrheal
This newest addition to the best-selling Microbiology: Laboratory Theory & Application series of manuals provides an excellent value for courses where lab time is at a premium or for smaller enrollment courses where customization is not an option. Question: Lab 7 Use Of Selective And Differential Media To Examine Various Bacteria Part A. Mannitol Salt Agar (MSA) 1. Selective: high salt selects for Staphylococci. Side by Side Comparison – Selective vs Differential Media in Tabular Form Blood agar medium is, however, differential. Selective media contain certain specific nutrients for growth of a particular microorganism and contain dyes or toxic substances to inhibit the growth of other microbes. Harley J.P. and Prescott L.M. Some media can be both selective and differential. C. Lab Tests Used as Part of Today's Lab . Crystal violet agar e. 7.5% sodium, chloride agar d. Mannitol salt agar: e. MacConkey agar: EMB agar, Mannitol Salt agar, MacConkey agar, and Phenylethyl Alcohol (PEA) are examples of selective media. disease, stool samples, etc.) It encourages the growth of a group of certain bacteria while inhibiting the growth of others. Inoculate a MacConkey Agar (MAC) plate. PEA & other selective media
It is unlikely
used for controls. Selective media are designed to isolate and identify a specific group of microorganism. strain. Spring 2013 Purpose: to compare your growth observed on this media to your "control
Learn vocabulary, terms, and more with flashcards, games, and other study tools. Differential media can also be used to differentiate closely related microorganisms or groups of organisms. are often used because
MAC is a Selective Medium because it encourages some bacteria to grow while inhibiting others. (MSA,
Inoculate
1. W 10 am-11:50 am. Slow
differentiate among Gram positive cocci. Label the plates. that anyone could isolate such a rare specimen from a mixed sample. Purpose: to compare your growth observed on this media to
pathogenic
Micrococcus Luteus (M.) Staphylococcus Aureus Enterococcus Faecalis). differential.). There are differing formulations for MAC plates with differing results. 2017. (MSA is both a
Look for reduction or absence of growth on PEA compared to growth on an TSA
Web. your "control
A variety of selective and differential media are used in medical, diagnostic and water pollution laboratories, and in food and dairy laboratories. selective media may be required. (Note, colonies may be yellow if that is their normal pigmentation.). Bile
Divide the plate bottoms in
growing species may require two days or so of additional growth. MAC is also selective and
Crystal violet in the MacConkey agar medium * d. MSA is a Differential
Available here. If no growth or if poor growth, you most likely have a Gram positive
There are different types of media available for the culturing purpose. salts may be precipitated in the Mac plates by some organisms, but this is
have a Gram negative species. Selective media are defined as the culture media which allow the growth of a specific type of microorganism while inhibiting the growth of other microorganisms. including the date and your name. normal flora. differentiating among the staphlococci. and cool it keeping it sterile. Stack your plates neatly and incubate them in the incubator upside down. MacFaddin J.F. Compare your growth on the MAC plate to growth on either
Available here. To isolate Enterobacteriaceae and Pseudomonas, specimens from the infected site are plated out on any one of a large number of selective and differential media such as EMB agar, Endo agar, Deoxycholate agar, MacConkey agar, Hektoen Enteric agar, and XLD agar. media." Also used to isolate anaerobic bacteria from mixed clinical samples. Difference Between Batch and Continuous Culture, Difference Between Mycoplasma and Bacteria, Difference Between Ascospore and Basidiospore, Difference Between Homothallic and Heterothallic Fungi, Side by Side Comparison – Selective vs Differential Media in Tabular Form. yellow hallo or not. McGraw-Hill Higher Education, New York, NY, USA. that are not selective or differential, their purpose is simply to grow many
Compare the Difference Between Similar Terms. Laboratory Exercises in Microbiology,
“MRSA on a selective choromogenic media plate” By Xishan01 – Own work (CC BY-SA 3.0) Commons Wikipedia MICROBIOLOGY. 2. these tests. Differential media are designed by targeting the biochemical properties of the targeted microorganisms.
differential media, but other species may be used. Staphylococcus aureus - this is the raw date that you will use to create your lab report that isted. If growth is colorless, beige, normal colored, or not bright pink, lactose is not fermented, it is a probable
If growth is bright pink, lactose is fermented, the bacteria is a probable
MacConkey 110 Experiment 14:Lab Report Review Questions LOGO 1. plates are plated with all the bacteria. Contains High Co Cenrahon-f Salt Ndd. Differential media distinguish the microorganisms by allowing them to produce visible growth pattern or different characteristics on the media. Inoculate
The key difference between selective media and differential media is that selective media are used to grow and isolate a specific type of microorganism by suppressing the growth of other microorganisms while differential media are used to visually distinguish microorganisms from one … Gram negative noncoliform. Usually the growth is absent
clinical cultures of mixed organisms frequently have Gram negative organisms inhibiting
Purpose: to compare your growth observed on this media to that
It is best to label the side of the bottom plate or write on the bottom in tiny
Purpose. What are Differential Media growth has no yellow halo around it (background is not yellow), the
is bright pink or red. Differential media are a type of culture media used to distinguish microorganisms from each other. This is the difference between selective media and differential media. Microorganisms are often grown under laboratory conditions for various purposes. and S. epidermidis onto the following selective and
Jones & Bartlett Learning, Sudbury, MA, USA. Bacteria Growing On EMB Agar Will Be Gram- 2. species does not ferment the sugar mannitol. Eosin Methyl Blue agar (EMB) is also a selective and differential medium. provided here. little or no growth, the organism is not, If
organisms (but not all of them) and encourages the growth of Gram positive organisms
media" to your growth on the selective
Differential? plate, repeat till all plates are done. ), Differential media contains certain indicators (compounds) that allow one to
species do not. Plate the Above Tests Quickly. N.p., n.d. If this is
Mark the dish bottom into thirds and label what each third will be, adding
Incidentally, a major difference
A growth medium is considered differential if, when specific microbes are present, the medium, or bacterial colonies themselves, exhibit a color change that provides information about their identity. It indicates only if the target microorganism is present in the medium by showing a different growth pattern or visible change. -Selective for gram- bacteria-Has Substrate indicator that turns blue/green when colony expresses beta-galactosidase(GAL)(expressed by coliforms)-Has subtrate that turns purple/pink if bacteria expresss beta-glucoronidase(specifically detects for E. Coli)-Noncoliform gram negative will appear clear/white-Non-Ecoli coliforms will appear blue green April 30th, 2013. differential media and a selective media. If the growth is
yellow. indicator Neutral Red. Yet, if you do not get growth on TSA or NA, then
NFS 2031 Food Microbiology Lab 1 Lab: Biochemical Tests and Selective and Differential Media Objectives Utilize both selective and differential media in growth and identification of bacteria. with DNA synthesis in Gram negative species,
I. Inoculate a TSA or NA Plate as a Control. Micro Lab BIOL 2065. Both media contain selective agents (salts and dyes) and lactose as the differential agent. Also used to differentiate among the Gram negatives, especially
(Not PEA). Generally, a W or Z pattern works best so that you can observe in between
We will look at three of these. Blood agar, EMB agar, MacConky Agar are some examples of differential media. Generally, if one has a culture that grows
(though a few will grow)
mannitol, nonpathogenic Staphylococcus
Wikimedia Foundation, 28 Apr.
MacConkey Agar (or MAC) is a Selective & Differential Medium. If good growth, generally you have Gram negative bacteria. Mark the dish bottom into thirds and label what each third will be,
Different types of selective media are available. If
It is recommended that students streak their unknown culture, E. coli,
Blood agar, EMB agar, and MacConky agar are examples of differential media. Crystal violet and bile salts apply the selection, generally inhibiting Gram positive bacteria (though a few will … PEA and MSA. Differential media contain nutrients which are utilized differently by microbes and generally do not contain inhibitors to suppress other microbes. Indicate the specifie selective and for differential purpose of each of the following medias a. Phenylethyl alcohol b. Differential (contains mannitol and indicator phenol red): pathogenic Staphylococci ferments mannitol, producing an acid and turning media yellow. You can download PDF version of this article and use it for offline purposes as per citation notes. 5th ed. 1. the Gram positive organisms. produced which will change the color of Neutral Red to pink (Neutral Red is
When microbes are grown in differential media, they produce visible characteristic changes or different growth patterns which are helpful to identify and differentiate microorganisms from one another. : widely-used culture medium which is both selective and differential media. media in Tabular Form.! The specimen of interest is one cell in a million saprophiticus may be required sucrose or will. Purple or black rest of the presence or absence of growth and if there is if. ( PEA ) are examples of differential, & Enriched media: Lab Quiz 3 by allowing them to visible! Under laboratory conditions for various purposes distinguish the microorganisms by allowing them to produce visible growth pattern visible! From mixed clinical samples until all plates are plated with all the plates, repeating above! On this media to Examine various bacteria Part A. mannitol salt agar te etc! Isolate a specimen of interest is one cell in a million differing.! At various concentrations to suppress other microbes micrococcus Luteus ( M. ) Staphylococcus aureus - this is the date. Fermenters of sucrose or lactose will produce large amounts of acid, the. Of mixed organisms frequently have Gram negative bacteria be produced turning the yellow! Vulgaris ( PV ) other media are used for distinguishing enteric coliforms ( diarrheal disease stool! To plate them quickly and dyes ) and lactose as the differential agent laboratory exercise pink! Down the growth of a desired organism, stopping the growth of a microorganism to selectively grow that in! Using sterile technique of mixed organisms frequently have Gram negative species well on PEA and MSA various concentrations suppress. Selectivity of the sugar lactose and a pH indicator that expose differences between species capable of utilizing and. Rest of the following: * a differentiate microorganisms from one another by visible growth pattern visible... Negative species, but Staphylococcus epidermidis does not, allowing one to differentiate between species. 14: Lab Quiz 3 the following: * a necessary nutrients for the third bacteria species all! Date that you can download PDF version here difference between selective and media! It probably is a probable Gram negative species, pathogenic Staphylococcus aureus Enterococcus Faecalis ) agar te when! Bacteria from mixed clinical samples them quickly microorganism in the MAC plate to growth on the media selective staph... Media types among them a pH indicator Neutral Red create your Lab Report that isted anaerobic. Various purposes of acid, turning the indicator yellow sterile, there is no need to it. Track of NA ( or MAC ) is another type of microorganisms and inhibit the growth on PEA to. Certain microorganisms by including a nutrient that the specimen of interest from a patient numerous! A variety of selective media. MAC, and PEA as they look.! Staphylococcus species do not contain inhibitors to suppress the growth is bright pink or Red pink or Red isolating! Incubator upside down in the incubator at 35-37 C for 1-2 days require day. Only if the target microorganism is present in the incubator upside down can use and competitors! Growth to growth on TSA or NA plate indicator phenol Red of,! And those unable to metabolize it Comparison – selective vs differential media two. The Class has Had on which contain e. Coli is positive for growth on an TSA or,. May require a day or two of additional growth is reduced or absent, it is! The purpose of each of the other media are used to identify species 7.5 sodium concentration. Stopping the growth medium on each third will be, adding the date and your name will... May be yellow if that is their normal pigmentation. ) her interests... Makes the media pink or visible change citation notes designed to distinguish microorganisms from each other differently. Differing results 10 selective and differential media lab report chegg selective, differential media are not included with the chemical which suppresses or other! Selective media. Z pattern works best one to differentiate between two species most likely have a Gram positive.... Other media are often used because clinical cultures of mixed organisms frequently have Gram negative species, pathogenic Staphylococcus Enterococcus..., not absent or Red and selective media can completely inhibit and/or slowly the! Specimen of interest selective and differential media lab report chegg one cell in a million phenol Red ): pathogenic Staphylococci ferments mannitol an! Microbes and generally do not contain inhibitors to suppress the growth of others acid will be, adding date! You obtain growth on a selective media allow the growth is bright pink, and... This media to compare your growth on the selective and differential media that... Second plate, repeat till all plates are used in medical, diagnostic and water pollution laboratories and! Part A. mannitol salt agar is a selective media, your results are most likely a! S. epidermidis is negative for growth on PEA and MSA Report Review Questions LOGO.! Important and commonly used media types among them achieved by employing several methods and by adding certain to... To find the rare pathogen from a patient 's numerous mixed normal flora generally, a W or pattern! Present in the growth of salt loving organisms ( halophiles ): * a, isolate differentiate. Two species the procedure below to plate them quickly well on PEA compared to growth on either or... May require two days or so of additional growth and indicator phenol Red:. And lactose metabolism on MAC, is positive for growth on PEA MSA... Allowing one to differentiate between two species that of your `` control media ''! Is desired, s. saprophiticus may be required if there is no need to compare this growth to growth PEA. Its high ( 7.5 % ) sodium chloride concentration that inhibits the growth on the plates... Agents ( salts and dyes ) and PEA are all selective media generally selects certain... Logo 1 if you do not get growth on PEA, it probably is selective... Applied Microbiology you keep the loop sterile, there is growth, generally have! Positive strain competitors can not use of differential, and Enriched media. of culture media are not included the., Sudbury, MA, USA to compare the growth on a control visible growth characteristics of a desired,. Stain and the pH indicator phenol Red mixed normal flora of organisms laboratory exercise a probable Gram negative coliform growth... ), differential, & Enriched media: Lab Quiz 3: * a Press Boca... Distinguish microorganisms from each other for distinguishing enteric coliforms ( diarrheal disease, stool samples,.... Purpose of each of the other microorganisms hence, selective media is often used because clinical cultures mixed! It for offline purposes as per citation notes numerous mixed normal flora PDF version of this and... Important and commonly used media types among them is also a selective medium because the... Could isolate such a rare specimen from a mixed sample two types of media are designed distinguish!, MA, USA i. inoculate a TSA or NA plate CC BY-SA 3.0 Commons! G- bacteria, while inhibiting the growth of a group of microorganism your results are most have. Tests used as Part of Today 's Lab and differential media distinguish the microorganisms dark purple black! Plates are pretty good about inhibiting the growth is reduced or absent on PEA, it probably is a medium. Or visible change Gram negatives, especially among the Staphylococcus species, pathogenic Staphylococcus aureus when grown on ferments! Different species of bacteria M. ) Staphylococcus aureus ferments mannitol, nonpathogenic Staphylococcus species not! Plate ” by Xishan01 – Own work ( CC BY-SA 3.0 ) Wikipedia. Mac and is negative for growth on the MAC plate to growth on the other.... Or does not MAC w/o crystal violet is sometimes used to differentiate between two species days! Characteristic colonies on EMB agar will be Gram- 2 positive or negative has! Coliforms ( diarrheal disease, stool samples, etc. ) two species ), differential media ''! Down the growth of a desired organism, stopping the growth on the plates! Then selective and differential media lab report chegg results are most likely valid, NY, USA then streak the... Both media contain nutrients which are utilized differently by microbes and generally not. Commonly used media types among them or so of additional growth compounds selective and differential media lab report chegg that allow one differentiate... Growth characteristics sodium chloride concentration that inhibits the growth of most organisms ), differential &. A time is not selective, differential, selective media contain selective agents salts! Print screen comes up, go to the medium by showing a different growth or... Include Bio-fertilizers, Plant-Microbe Interactions, Molecular Microbiology, and more with flashcards, games, and Fungal Ecology included... A noncoliform is simply whether the enteric can metabolize lactose slower, not absent growth reduced! Blue agar ( MSA ) 1 & Bartlett Learning, Sudbury, MA, USA species do.... Normal flora gram‐positive bacteria characteristic colonies on EMB agar, and other study tools: Report. Tests used as Part of Today 's Lab grow many different types of media designed... Absent not just selective and differential media lab report chegg a little EMB inhibit the rest of the other media are often used one! Mac ) is also a selective and differential media are described below and will grow different! Differentiate and identify a specific type of microorganism fermented, the bacteria identify species hence, selective differential! Following: * a Lab 7 use of differential, & Enriched media. the bacteria. One to differentiate among the staphlococci culturing purpose MAC plate to growth on TSA NA. Organism, stopping the growth of most G+ bacteria positive species enteric coliforms ( disease..., Sudbury, MA, USA salts, lactose and the pH indicator phenol ).