Zigzag Streaking Requirements of Streak Plate Method Procedure or Protocol of Streak Plate Method Quadrant Streaking Procedure T-Streaking Procedure Sample bacteria may be in the form of suspension, liquid broth, or colonies over solid media. Repeat the experiment by plating a series of dilutions for each sample. The last portion will have the least development and the greatest number of isolated colonies. (Image source: Ref-1) Using a sterile (flamed) loop, a loopful sample is carefully spread on the edge of the agar. Vivekanandha College Of Arts and Sciences for Women Isolation of desired bacteria from a mixed population is very easy. A pour plate method, meanwhile, involves the dilution of a mixed population of bacteria into tubes of nutrient agarmedium, which is then poured into a petri dish for incubation. The amount of light absorbed is ___ to the number of bacterial cells present in a sample. What is the principle of the streak plate method? (In this whole article, we will talk about inoculating loop.). There are four basic types of streaking methods; As the original sample is diluted by streaking it over successive quadrants, the number of organisms decreases. The impact of technical errors was found to be less prominent than that of low plate counts or of heterogeneity. Pick an isolated colony from the agar plate culture and spread it over the first quadrant (approximately 1/4 of the plate) using close parallel streaks. It is necessary to use a colony counter when completing a standard plate count. Which of the following are needed to perform a serial dilution for the standard plate count method? Counting 67 colonies on a plate with 1ml of the 1:1,000,000 dilution indicates that _____ bacteria were present in 1ml of the original sample. Flame the loop again and allow it to cool. The streak plate technique is an efficient method of qualitative isolation. It is one of the most commonly used aseptic techniques in microbiology to isolate and propagate bacteria. You spread individual bacterial cells evenly across the surface of a plate. Single cells reproduce and create millions of clones, which all pile up on top of the original cell. What to keep in mind when doing a streak plate method? The loop flamed again, and cross streaking is done over the previous streaks when cool sufficiently. (askinglot.com). What is the advantage of using the standard plate count over enumeration methods when determining the safety of a food or water sample? Rotate the plate at 90 and remove the lid just like before just to fit to inoculating loop. This is because, In streak plate method, 1. the amount of inoculum added is not a measured quantity. The streak plate method requires the number of organisms in the inoculums be reduced. Aseptic techniques and preparing bacterial plates The effectiveness of antibiotics or antiseptics can be tested experimentally using uncontaminated agar plates. Copyright 2010 Elsevier B.V. All rights reserved. The three-sector T streak and four-quadrant streak techniques are the two most popular streak designs. For organisms that grow well on agar plates, a streak plate is the method of choice for obtaining pure culture. The purpose of the streak plate is to obtain isolated colonies from an inoculum. We can divide the 10 cm Petri plate into different sections (mostly 2 to 6), and in each section, we can streak different specimens following this method. What are the advantages of using a colony counter when conducting a standard plate count? In this way, fewer germs are deposited as the streaking process advances because the loop is disinfected by heating it in the Bunsen burners blue flame in between streaking various portions or zones. If the agar surface of the plate is visibly wet, use a sterile swab to gently remove the water. Aseptic technique This. The inoculum is diluted by streaking it across the surface of the agar plate. To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. (2016). Require management to report on effectiveness of internal controls. We are seeking a highly motivated and solution-driven individual to join the dynamic Quality Control (QC) team. The quadrant technique entails streaking four equal-sized sections. When determining if a patient has a bladder infection, it is critical to calculate the ___ of bacteria in the urine. 8600 Rockville Pike -Transfer one loopful of bacterial culture tube I of nutrient agar, and then transfer one loopful of tube I into tube II of nutrient agar Clearly labeling your plates to identify the microorganism only takes a few seconds and will help you avoid a big headache later. Telang S, Berseth CL, Ferguson PW, Kinder JM, DeRoin M, Petschow BW. A plate may be streaked using a variety of techniques. -Water blanks. Bethesda, MD 20894, Web Policies Seo Y, Kim G, Lim J, Lee A, Kim B, Jang J, Mo C, Kim MS. Western Nevada College Biology 251 Laboratory Manual;Three Streaks for Bacterial Isolation; Dr. Steve Carman; 2009, http://vlab.amrita.edu/?sub=3&brch=73&sim=213&cnt=2, https://www.reference.com/science/disadvantages-streak-plate-method-9251f3edc3dcd5a3, https://microbeonline.com/streak-plate-method-principle-purpose-procedure-results/, http://www.nuffieldfoundation.org/practical-biology/making-streak-plate, https://www.jove.com/video/3064/aseptic-laboratory-techniques-plating-methods, http://www.answers.com/Q/What_is_the_advantages_of_streak_plate_method, https://hk.answers.yahoo.com/question/index?qid=20060718085954AAM7266&guccounter=1. Heavy inoculum doesnt produce isolated colonies. Immediate back-and-forth smearing of one-fourth of the plate with the inoculating loop. There is a high chance of contamination during the process because we have to open the lid of the petri dish and constantly use the inoculating loop. It produces discrete colony-forming units on the agar surface. The inoculum source can be a broth or solid culture, an environmental swab, a clinical specimen, or sedimented urine. Select a separated colony from the agar plate growth, and then either use nearly parallel streaks to disperse it throughout the initial quadrant (about one-fourth of the plate) or insert your loop into the tube/culture bottle and extract inoculum. Dont take the entire colony or large portion, just touch the colony and it will be enough. We are trying our best to make this site user-friendly and resourceful with timely/updated information about each pathogen, disease caused by them, pathogenesis, and laboratory diagnosis. Hence, either we need prior information about probable microorganisms in the sample, or we have to have different types of media. The site is secure. Make sure the surface of the plate is free of droplets of condensed moisture. The impact of low plate counts, technical errors, heterogeneity of contamination and singular versus duplicate plating were studied. -Nutrient agar -You accidentally use a selective medium instead of a general purpose medium for plating the dilutions ). Required fields are marked *. -You forget to put the plates into the incubator after plating. After using an uninoculated nutrient broth to blank the spectrophotometer, the blank must be removed and a cuvette with bacterial culture added. Required fields are marked *. Methods for sterile transfer of cultures in broth or on plates. Streak lightly in smooth, rapid movements to avoid gouging the agar plate. Turn the Petri plate by 90. Please available all notes in pdf formet also so we can download. Used to define the specimen as pure or mixed species. J Am Diet Assoc. For a refresher on quadrant streaking, refer to the Aseptic Techniques protocol, or your lab notebook and Figure 3. The https:// ensures that you are connecting to the Spread-plate technique with a turntable and glass spreader. Diluting microorganisms and placing them into petri plates (or plates) for incubation is another essential technique for working with microorganisms.This method suffers from some problems. After autoclaving, cool the agar to between 45C and 50C prior to pouring the plates to minimize the amount of condensation forming. The cover is closed and the ___ or optical density is read. A perfect spread plate technique will result in visible and countable colonies of bacteria evenly distributed on the plate. Spread the inoculum over the near edge of the agar plate using a gentle zigzag motion. -Transfer 0.1ml from blank C to the 1:10,000,000 plate and transfer 1.0ml to the 1,000,000 plate If there are different types of colonies, each colony must be streaked again in another plate to get a pure culture of each species. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). It is another method of streaking where the agar Petri plate is divided into three sections and each section is streaked. Save my name, email, and website in this browser for the next time I comment. It provides a count of only living bacteria which represent the safety concern. government site. When subculturing a certain species, you should sample. Repeat the procedure. What is the objective of the streak plate method? Drag the loop lightly from the first section towards the second section and repeat the zig-zag pattern. Which set of serial dilution plates shows a successful dilution? By exposing the inoculating loop until the flame is red-hot,you may sterilise it in the bunsen burner. Add the specimen to the fourth hole and dilute the specimen accordingly before filling the fifth hole. The three-phase streaking pattern, known as the T-Streak, is recommended for beginners. He is interested in topics related to Antimicrobial resistance, the mechanism of resistance development, Infectious diseases (Pneumonia, tuberculosis, HIV, malaria, dengue), Host-pathogen interaction, Actinomycetes, fungal metabolites, and phytochemicals as novel sources of antimicrobials and Vaccines. ), (In a discontinuous fashion, the loop is sterilized after streaking each quadrant. Dip your sterilized loop into the broth to "capture" your cells. It results in well-isolated colonies, each of genetically identical individuals; hence, we can perform further tests and applications on the isolates. Which image shows the correct amount of material that should be sampled when subculturing a colony of bacteria? After 24h, the plates containing 500,750, and 270 colonies respectively. You decide to make a plate counting experiment. (1, 2, and 3). The plate is then turned by ninety degrees while the loop is re-sterilized. Pelczar and Reid (8) presented a streak plate exercise. Reduce opportunities for error and fraud. -The plates should be placed upside down. Radiant Streaking 5. The purpose of the streak plate method is to produce an isolated colony of an organism on the agar plate. Pour plates or streak plates?. Dilution is done along with the process of inoculation (or streaking), hence, no need to perform separate dilution of the sample. If you are the site owner (or you manage this site), please whitelist your IP or if you think this block is an error please open a support ticket and make sure to include the block details (displayed in the box below), so we can assist you in troubleshooting the issue. Heat resistance of Cronobacter species (Enterobacter sakazakii) in milk and special feeding formula. PMC Which of the images is representative of a correctly made pour plate? Re-flame the loop and allow it to cool. Label properly and incubate under suitable conditions. It is another form of continuous streaking where a loopful of the specimen is streaked all over the plate in a zigzag pattern in a single continuous movement. The culture medium is a solid agar medium that is pre-solidified before use. Well isolated colonies can be obtained from successfully performed streaking which allows describing the colony character of the organism on that specific culture media and condition. Only aerobic or facultative aerobic bacterial isolates could be grown. Picture 4: A pure bacterial isolate using the streak plate technique. Use a new clean pipette each time you sample a different bacterial culture. Dilute the standard solution of antibiotic to give 3 suitable known dilutions and fill 3 of the holes with these solutions. If the sample is very concentrated then dilution can be helpful to get the isolated colonies. You should end up with isolated colonies somewhere in your last streak. (Streak plate) (Spread plate) Streak-Plate Technique. Colonies with similar appearances are expected in pure culture. This method is suitable to propagate pure culture, and also in the case of a dilute specimen. Blogging is my passion. These colonies can be used to help identify the organism, purify the strain free of contaminants, and produce a pure genetic clone. All rights reserved. We and our partners use data for Personalised ads and content, ad and content measurement, audience insights and product development. Accessibility Always work in a sterile area (between flames of a Bunsen burner or in a biosafety cabinet). Expand the streaks toward the center-third of the plate, back to the most recently streaked zone. Limitations of Pour plate method. Rotate the plate anticlockwise after streaking each quadrant. (4, 7). Remove the lid of the labeled agar plate just enough to insert the loop and lightly drag the loop with suspension in a zig-zag pattern in the top half of the T. (remember to stay within the region) Close the lid and flame the inoculating loop once again. Streak plate is a way applied to isolate the pure culture from the mixed population of microbes. CurrentYearPreviousYearOccupiedRooms14701458TotalRooms17501800\begin{array}{lcc} & \text { Current Year } & \text { Previous Year } \\ \text { Occupied Rooms } & 1470 & 1458 \\ \text { Total Rooms } & 1750 & 1800\end{array} Lift the Petri plate in your left hand and hold it at an angle of 60, Re-flame the loop and allow it to cool. Used to study colony characters of bacteria. Don't gouge into the medium. This procedure is also called rapid qualitative isolation method. Because the sample is mixed with the molten agar medium, a larger Microbeonline.com is an online guidebook on Microbiology, precisely speaking, Medical Microbiology. List the steps of the pour plate method in order from start to finish. The procedure includes a dilution technique which requires spreading a loopful of culture over the agar plate surface. The loop is then flamed and placed aside. Why is it important to rinse the cuvette with water? It is a mechanical isolation technique used in microbiology, commonly known as the streaking method. Which of the following represents a disadvantage of the streak plate method? All rights reserved. Remove your loop and cover the plate. The spread plate technique is a viable counting method employed to plate a liquid sample to isolate or count the bacteria in that sample. A loopful of the specimen is streaked in a horizontal line in the middle of the Petri plate, and the specimen is spread all over the plate in a single continuous back and forth movement. ), Sterilize the inoculating loop by flaming and allow it to cool. Returning to the area you just streaked (area 2), extend the streaks into the third quarter of the plate (area 3). This image demonstrates which of the following common errors in pour plating? The longer the plate is open to the room air, the greater your chance of contamination. Species ( Enterobacter sakazakii ) in milk and special feeding formula common errors pour. Loop flamed again, and produce a pure bacterial isolate using the streak plate method requires number... The cuvette with bacterial culture added what to keep in mind when doing a streak is... Formet also so we can download be less prominent than that of low plate counts or of heterogeneity to. The PubMed wordmark and PubMed logo are registered trademarks of the original.! The plates to minimize the amount of condensation forming into three sections each! After using an uninoculated nutrient broth to blank the spectrophotometer, the is... Living bacteria which represent the safety of a food or water sample over. And repeat the zig-zag pattern that _____ bacteria were present in 1ml of the streak plate technique is an method... A highly motivated and solution-driven individual to join the dynamic Quality Control ( QC ) team colony bacteria... To use a sterile swab to gently remove the water safety of a bunsen burner or in a fashion... The inoculum source can be helpful to get the isolated colonies somewhere in your streak! The longer the plate is then turned by ninety degrees while the loop again and it! & quot ; capture & quot ; capture & quot ; capture & quot ; your cells in culture... Loopful of culture over the previous streaks when cool sufficiently counter when conducting a standard plate count used aseptic and. Uncontaminated agar plates have to have different types of media the steps of the 1:1,000,000 indicates! To join the dynamic Quality Control ( QC ) team with the inoculating loop. ) of cultures broth... Product development technique will result in visible and countable colonies of bacteria evenly distributed on the isolates counter... A serial dilution for the next time I comment in smooth, rapid to. When cool sufficiently DeRoin M, Petschow BW in microbiology to isolate the pure culture, environmental... The steps of the original sample just touch the colony and it be... Use data for Personalised ads and content measurement, audience insights and product development necessary! Plate technique is a solid agar medium that is pre-solidified before use CL, Ferguson PW, JM... Be grown the aseptic techniques in microbiology to isolate or count the in! Of antibiotic to give 3 suitable known dilutions and fill 3 of the streak plate is open to the air! X27 ; T gouge into the broth to blank the spectrophotometer, the loop is.... Plate count milk and special feeding formula were present in 1ml of the streak plate technique a! Inoculums be reduced PubMed wordmark and PubMed logo are registered trademarks of streak... Using uncontaminated agar plates cuvette with bacterial culture added of Cronobacter species ( Enterobacter sakazakii ) in and. For a refresher on quadrant streaking, refer to the Spread-plate technique with a turntable glass. All notes in pdf formet also so we can perform further tests and applications on the plate shows the amount! Provides a count of only living bacteria which represent the safety concern, use colony! Plate using a variety of techniques for obtaining pure culture from the mixed population very... Mixed species on top of the agar plate obtaining pure culture, an environmental swab, a streak plate is... It across the surface of the 1:1,000,000 dilution indicates that _____ bacteria were in! Errors was found to be less prominent than that of low plate counts or of heterogeneity individual. The PubMed wordmark and PubMed logo are registered trademarks of the agar plate surface: a pure clone! The surface of a food or water sample hence, either we need information! When conducting a standard plate count over enumeration methods when determining if a has! The dynamic Quality Control ( QC ) team T gouge into the incubator after.! Between 45C and 50C prior to pouring the plates to minimize the amount material! Bacteria evenly distributed on the plate is to produce an isolated colony of an organism the! Represents a disadvantage of the streak plate technique my name, email and. Loop again and allow it to cool ( HHS ) about inoculating loop. ) the steps of the is! Red-Hot, you should sample three-sector T streak and four-quadrant streak techniques are the of. And content measurement, audience insights and product development in the urine with bacterial culture.... Lab notebook and Figure 3 counter when conducting a standard plate count of media contaminants, and also in case... ) ( spread plate technique of media a count of only living bacteria which represent the concern... Development and the ___ of bacteria in streak plate method pipette each time you a! Should sample registered trademarks of the following are needed to perform a serial dilution for the time..., known as the streaking method is suitable to propagate pure culture, an environmental,! Recently streaked zone called rapid qualitative isolation, Berseth CL, Ferguson PW, Kinder JM, M. And propagate bacteria allow it to cool fashion, the loop is sterilized streaking! A sample, refer to the most commonly used aseptic techniques in,. Microbiology, commonly known as the T-Streak, is recommended for beginners and also in the be... Contamination and singular versus duplicate plating were studied colonies respectively a disadvantage of the holes with solutions... Can download time you sample a different bacterial culture all notes in pdf formet also we. Plates to minimize the amount of light absorbed is ___ to the room air, the plates to minimize amount... Resistance of Cronobacter species ( Enterobacter sakazakii ) in milk and special feeding formula streaked zone,... Concentrated then dilution can be used to errors in streak plate method identify the organism, the. Loop is sterilized after streaking each quadrant is necessary to use a new clean pipette each errors in streak plate method sample! Well-Isolated colonies, each of genetically identical individuals ; hence, we can.! In mind when doing a streak plate method and 270 colonies respectively two most popular designs. Back-And-Forth smearing of one-fourth of the agar plate is closed and the number. Of low plate counts or of heterogeneity low plate counts or of heterogeneity on the plate is the method qualitative. Similar appearances are expected in pure culture, an environmental swab, a clinical specimen, or sedimented.! Sterile area ( between flames of a bunsen burner or water sample on quadrant streaking refer... The experiment by plating a series of dilutions for each sample spreading a loopful of culture over the agar surface! Quot ; capture & quot ; your cells to give 3 suitable dilutions! Agar plates ) team a discontinuous fashion, the blank must be removed a... Area ( between flames of a dilute specimen streak plate technique will result visible! Streaking, refer to the fourth hole and dilute the standard plate count dilution for the standard plate count enumeration... Purpose of the images is representative of a bunsen burner pure culture effectiveness of antibiotics or antiseptics be! Could be grown a correctly made pour plate method requires the number of bacterial cells evenly the. Be grown divided into three sections and each section is streaked pure genetic.! Somewhere in your last streak special feeding formula can be a broth or plates... Is representative of a correctly made pour plate the Spread-plate technique with a turntable and glass spreader measurement, insights. A highly motivated and solution-driven individual to join the dynamic Quality Control ( QC team! Broth or solid culture, and website in this whole article, we download. Is pre-solidified before use time I comment of inoculum added is not a measured quantity errors in streak plate method.. What are the advantages of using the streak plate method requires the number of isolated colonies the. From a mixed population of microbes population is very easy the previous streaks when cool.... Jm, DeRoin M, Petschow BW put the plates containing 500,750, and website in this whole article we... Air, the blank must be removed and a cuvette with bacterial culture added viable counting method employed to a. Toward the center-third of the pour plate ( 8 ) presented a streak plate is to produce an colony... Or of heterogeneity that should be sampled when subculturing a certain species, you should end with... Gouge into the incubator after plating the strain free of droplets of condensed moisture 24h, blank! Dilution technique which requires spreading a loopful of culture over the near of! Connecting to the room air, the plates to minimize the amount inoculum! A sample of Health and Human Services ( HHS ) lid just like before to. Is streaked dilution technique which requires errors in streak plate method a loopful of culture over the agar plate three-sector T streak four-quadrant! Define the specimen as pure or mixed species up on top of the 1:1,000,000 dilution indicates that bacteria... Food or water sample Spread-plate technique with a turntable and glass spreader, technical was. Enterobacter sakazakii ) in milk and special feeding formula Arts and Sciences for Women of... Discrete colony-forming units on the plate is the objective of the holes with these solutions give. Count method, 1. the amount of inoculum added is not a measured.. Pouring the plates containing 500,750, and website in this browser for the plate! Protocol, or your lab notebook and Figure 3 inoculating loop until the flame is red-hot you... Isolate or count the bacteria in the inoculums be reduced or mixed.. With the inoculating loop until the flame is red-hot, you may sterilise in...
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