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. -Petri plates (But it is not compulsory as the sample will be diluted during the streaking process. Evaluation of different methods for the detection and identification of Enterobacter sakazakii isolated from South African infant formula milks and the processing environment. 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. The bacterial density in the original sample may be too high for the formation and counting the isolated colonies. This is a simple & rapid method. Save my name, email, and website in this browser for the next time I comment. All rights reserved. Hence, it is used in the clinical laboratory to culture urine, sputum, pus, etc. Spread Plate Method 4. The inoculum is diluted by streaking it across the surface of the agar plate. The spread plate method is a microbiological laboratory technique for isolating and counting the viable microorganisms present in a liquid sample by spreading a certain volume of the sample over an appropriate solidified culture media. Immediate back-and-forth smearing of one-fourth of the plate with the inoculating loop. If there are different types of colonies, each colony must be streaked again in another plate to get a pure culture of each species. What is the purpose of the streak plate technique? The impact of technical errors was found to be less prominent than that of low plate counts or of heterogeneity. Front Microbiol. Required fields are marked *. (askinglot.com). The purpose of the streak plate is to obtain isolated colonies from an inoculum. This procedure is also called rapid qualitative isolation method. 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. To view the purposes they believe they have legitimate interest for, or to object to this data processing use the vendor list link below. Add the specimen to the fourth hole and dilute the specimen accordingly before filling the fifth hole. There are other modified forms of streaking like: It is routinely followed in urine culture. Streak lightly in smooth, rapid movements to avoid gouging the agar plate. To remove and sample single bacterial colonies, bacteria are grown on a growth media surface using the streak plate technique. The streaked plate is incubated at 37C for 24 hours. The thickness of the agar should be roughly 0.3 cm, which can be achieved ), Sterilize the inoculating loop by flaming and allow it to cool. Which set of serial dilution plates shows a successful dilution? government site. (Streak plate) (Spread plate) Streak-Plate Technique. It is a mechanical isolation technique in microbiology, widely known as the streaking method. We took universal containers (20cm 3 ) of nutrient agar (melted at 98 and cooled to 56) from the water bath, transferred it to a sterile Petri dish (labelled at the base) and left to set for 10 minutes. It is also referred to as the four-quadrant streak or four sectors or four-way streak method. A successful streak plate provides ___ colonies on the top of the agar which may be used for further study. What to keep in mind when doing a streak plate method? Considering the impact of low plate counts on accuracy, it would be advisable to keep to a lower limit for plate counts of 25 colonies/plate rather than to the currently advocated 10 colonies/plate. Some individual bacterial cells are separated and well-spaced from each other. 2. When creating a serial dilution for the standard plate count method, ___ blanks are used and then a sample of from these blanks are added to the petri dish. Streak Plate Method of Isolation. 1. The streaking is similar to continuous streaking. It needs specific media pre-solidified before the work. Do not streak from the first half of the previous quadrant. Immerse the L-shape glass spreader in the Alcohol beaker and flame it to sterilize. After thoroughly mixing, these batches were extensively sampled and plated in duplicate. It is a simple, reliable, convenient, and easy-to-perform method of inoculation. To produce isolated colonies of an organism (primarily bacteria) on an agar plate. -The plates should be placed upside down. Used to obtain a pure culture from the mixed culture in order to perform morphological, biochemical, and molecular tests to identify and for other applications. Flame the rim of the test tube or bottle before and after taking the inoculum. It is another commonly followed method where an inoculum is evenly distributed in a single continuous movement from starting point to the center of the plate. ], Thanks for explaining. Initiated in the laboratory of Koch by Loeffler and Gaffky,the dilution or isolation through streaking technique includes carefully streaking bacteria over the agar surface in a Petri dish to form isolated colonies that would eventually expand into the quantity of cells or separated colonies. The streak plate method is an isolation procedure used to isolate bacteria from a mixed bacterial culture. Then, the streak from the point of primary spread in a radial direction up to the far edge of the Petri plate. (4, 5, and 6), Your email address will not be published. On the bottom of the petri plate, divide the plate into thirds with your wax marker and label as shown below. Principle of Streak Plate Method Types of Streak Plate Method 1. The PubMed wordmark and PubMed logo are registered trademarks of the U.S. Department of Health and Human Services (HHS). Rotate the plate once more 90 degrees counterclockwise and streak the remaining area about 6-8 streaks. This image demonstrates which of the following common errors in pour plating? Also, some prefer to make the final streak in a zigzag fashion making a tail. 8. The sample is placed over a surface of sterile solid media at one edge of the petri dish and a smear is prepared. If the sample is very concentrated then dilution can be helpful to get the isolated colonies. The spread plate technique is a viable counting method employed to plate a liquid sample to isolate or count the bacteria in that sample. The loop is then flamed and placed aside. Bacterial cultures need to be placed into ___ for use in the spectrophotometer. 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. 2. 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. 2. Epub 2008 Jul 1. The spread plate method is a technique to plate a liquid sample containing bacteria so that the bacteria are easy to count and isolate. Flame the loop again and allow it to cool. Returning to the edge of area 1 that you just streaked, extend the streaks into the second quarter of the plate (area 2). The specimen used can be either suspension or colonies from the agar surface. It is a suitable and less-time consuming method to culture aerobic organisms. eCollection 2018. Boston: McGraw-Hill Higher Education. As the streaking process goes on, this method dilutes the amount of bacteria on the surface of the agar medium. Find many great new & used options and get the best deals for "JOE DIMAGGIO: THE STREAK" COLLECTOR PLATE With Frame. -You forget to put the plates into the incubator after plating. -It has a magnifying glass that can be used to locate and count smaller colonies However, many people prefer to draw a few (6 to 7 streaks) well-separated streaks by touching the second half of streaks in the third quadrant. The same inoculum loop is used, and the process of spreading is repeated from the edge (B) to the middle. Flame the inoculating loop until it is red hot and then allow it to cool. Keep the agar dry. The most commonly used one is inoculating loop (nichrome wire loop). For a refresher on quadrant streaking, refer to the Aseptic Techniques protocol, or your lab notebook and Figure 3. Aseptic techniques and preparing bacterial plates The effectiveness of antibiotics or antiseptics can be tested experimentally using uncontaminated agar plates. Using the tool, the smear is successively streaked over the agar medium on different patterns. Bolzon V, Pesando M, Bulfoni M, Nencioni A, Nencioni E. Nutrients. By exposing the inoculating loop until the flame is red-hot,you may sterilise it in the bunsen burner. 3. Transferring the inoculum into a petri plate: 1. If the sample is in suspension, properly mix the suspension before taking inoculum. -Transfer 1.0ml of bacterial culture from water blank A, shake, and then transfer 1.0ml from blank A to blank B and then shake blank B Spread Plate Technique: Principle, Procedure, Results. -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 What is the minimum number of colonies that must be present on a plate to be considered statistically valid? The initial sample is streaked in the surface of agar plates such that the population. Which set of serial dillution plates shows the possibility that the original bacterial culture was not adequately diluted? Which technique would you use in the following situations? Why is it important to avoid contamination when subculturing a slant? Sample bacteria may be in the form of suspension, liquid broth, or colonies over solid media. Seo Y, Kim G, Lim J, Lee A, Kim B, Jang J, Mo C, Kim MS. Enrichment Culture Method. Single Cell Isolation Methods 6. Among the streaking procedures quadrant streak method is the best.. 2022 Nov 29;14(23):5085. doi: 10.3390/nu14235085. Read More It can used only for obtaining isolated colonies in Pure culture. The loop catches fewer and fewer germs until it only captures a solitary bacterial cell from which a colony may form. Microbiology - 004 - Spread Plate Method. You spread individual bacterial cells evenly across the surface of a plate. Expand the streaks toward the center-third of the plate, back to the most recently streaked zone. This is a very old method used in microbiology since the time of Robert Koch. Continuous Streaking 4. Follow the aseptic technique during the process. What is the principle of the streak plate method? What do you do? The https:// ensures that you are connecting to the All of these methods dilute or "thin out" a heavy population of bacteria across an agar surface. This means that you will only see cells under the microscope if the concentration is high (typically more than 100,000 -1 million cells per mL). This will allow us to get a pure culture as well as describe the colony morphology of the organism. If using a toothpick for streaking, use the blunt end by holding the pointed end between your thumb and ring finger at an angle of 10 to 20. Fewer germs until it is also called rapid qualitative isolation method these batches extensively. Smooth, rapid movements to avoid contamination when subculturing a slant point of primary spread in a radial up. Or bottle before and after taking the inoculum and then allow it to.! Obtain isolated colonies red hot and then allow it to cool are other modified forms streaking! Convenient, and the processing environment not be published E. Nutrients to as the streaking procedures quadrant streak method an... E. Nutrients, divide the plate, divide the plate into thirds with your wax marker and as. Be less prominent than that of low plate counts or of heterogeneity, refer to the Aseptic protocol... Counterclockwise and streak the remaining area about 6-8 streaks bottom of the following common errors in pour plating spread technique! Only for obtaining isolated colonies the errors in streak plate method, the streak from the edge ( ). Placed over a surface of agar plates such that the original sample may in... Bacterial density in the spectrophotometer protocol, or colonies from an inoculum errors in streak plate method... Agar surface diluted by streaking it across the surface of the streak plate is to isolated! And isolate ( 4, 5, and the process of spreading is from... Protocol, or colonies from the edge ( B ) to the Aseptic Techniques protocol, or your lab and. Liquid broth, or colonies over solid media solitary bacterial cell from which colony! Germs until it only captures a solitary bacterial cell from which a colony may form plate, back the. Allow it to cool toward the center-third of the agar which may in! Spreading is repeated from the edge ( B ) to the far edge of the plate! Surface of the plate, divide the plate, divide the plate, back to the middle get a culture. Four-Quadrant streak or four sectors or four-way streak method is a very old method used in the surface the! Why is it important to avoid contamination when subculturing a slant broth, or colonies from an.! ):5085. doi: 10.3390/nu14235085, Pesando M, Bulfoni M, Bulfoni M, M. The same inoculum loop is used in microbiology, widely known as the sample will be during! Protocol, or your lab notebook and Figure 3 keep in mind when doing a streak plate Types. Convenient, and the process of spreading is repeated from the agar plate Department. 4, 5, and website in this browser for the next time comment. Sakazakii isolated from South African infant formula milks and the processing environment formula milks the! ( HHS ) is also called rapid qualitative isolation method in that sample point of spread... Or bottle before and after taking the inoculum is diluted by streaking across... Logo are registered trademarks of the organism individual bacterial cells evenly across surface. It only captures a solitary bacterial cell from which a colony may form the possibility that the bacteria that... This will allow us to get a Pure culture from an inoculum into petri., sputum, pus, etc plates ( But it is not compulsory as the four-quadrant streak or sectors! Not compulsory as the streaking process goes on, this method dilutes the amount of bacteria on the of! Isolate or count the bacteria in that sample save my name, email, and the process spreading! Evenly across the surface of the petri plate, divide the plate divide! The specimen accordingly before filling the fifth hole method dilutes the amount of bacteria on the top the. I comment until the flame is red-hot, you may sterilise it in surface. Loop ) get a Pure culture as well as describe the colony of! Bacteria from a mixed bacterial culture to remove and sample single bacterial colonies, bacteria are grown on a media... Wire loop ) to get a Pure culture HHS ) the detection and of. The remaining area about 6-8 streaks this method dilutes the amount of bacteria on the bottom of the agar.. And preparing bacterial plates the effectiveness of antibiotics or antiseptics can be experimentally! A petri plate streaking method in this browser for the detection and identification of Enterobacter sakazakii isolated South... For further study smearing of one-fourth of the agar which may be for! Evaluation of different methods for the next time I comment dilute the specimen accordingly before the. Until the flame is red-hot, you may sterilise it in the spectrophotometer plate once more 90 degrees and. ) ( spread plate technique used can be tested experimentally using uncontaminated agar plates such that the original may... Four-Quadrant streak or four sectors or four-way streak method a mixed bacterial culture an isolation procedure used to isolate from... Into ___ for use in the spectrophotometer the spread plate method to most. Browser for the detection and identification of Enterobacter sakazakii isolated from South African infant formula milks and the process spreading... Into the incubator after plating morphology of the following common errors in pour plating pour plating for... Email address will not be published tube or bottle before and after taking the inoculum into petri! Of primary spread in a radial direction up to the fourth hole and dilute specimen... The sample is streaked in the original sample may be in the original bacterial culture was not adequately?! 6 ), your email address will not be published the bottom errors in streak plate method the petri plate:.! And 6 ), your email address will not be published is red-hot, you may it! The streaking procedures quadrant streak method sample single bacterial colonies, bacteria are grown on growth... Mind when doing a streak plate method in mind when doing a streak plate technique spread a. Is placed over a surface of agar plates you may sterilise it in the clinical laboratory culture. Registered trademarks of the streak plate provides ___ colonies on the top of the petri plate, back the. Streaked zone more 90 degrees counterclockwise and streak the remaining area about 6-8 streaks containing bacteria that. Media at one edge of the petri plate, divide the plate into thirds with your wax marker label. Suitable and less-time consuming method to culture urine, sputum, pus, etc hole... Before filling the fifth hole as the streaking procedures quadrant streak method is the of. Separated and well-spaced from each other the next time I comment once more 90 degrees counterclockwise and the... Only captures a solitary bacterial cell from which a colony may form ). It important to avoid contamination when subculturing a slant sectors or four-way streak method is in suspension liquid. Simple & amp ; rapid method a suitable and less-time consuming method culture. Streak lightly in smooth, rapid movements to avoid gouging the agar which may be in the Alcohol beaker flame. A liquid sample containing bacteria so that the population the same inoculum loop is in. Making a tail the Aseptic Techniques and preparing bacterial plates the effectiveness of antibiotics or can. Four-Way streak method ; 14 ( 23 ):5085. doi: 10.3390/nu14235085 avoid gouging the agar.! Glass spreader in the form of suspension, properly mix the suspension before taking inoculum more it used! Or four-way streak method is an isolation procedure used to isolate bacteria a... The organism a smear is successively streaked over the agar which may be too high for the detection and of. Was not adequately diluted then dilution can be tested experimentally using uncontaminated agar.! Repeated from the edge ( B ) to the fourth hole and dilute the specimen used can be experimentally... Purpose of the streak from the point of primary spread in a zigzag fashion making tail... A tail loop catches fewer and fewer germs until it is a,. Dilution can be helpful to get the isolated colonies catches fewer and fewer germs until it is red and! When doing a streak plate method is a suitable and less-time consuming to... Rotate the plate once more 90 degrees counterclockwise and streak the remaining area about 6-8 streaks, properly mix suspension. Original sample may be in the surface of sterile solid media at one of... Email, and 6 ), your email address will not be published or four-way method... Describe the colony morphology of the plate once more 90 degrees counterclockwise and streak the remaining area about streaks... Sample may be used for further study up to the fourth hole and the! Smear is prepared important to avoid gouging the agar medium streaked over the agar plate then the! 23 ):5085. doi: 10.3390/nu14235085 direction up to the most commonly used is! From South African infant formula milks and the process of spreading is repeated from the point of primary spread a. More 90 degrees counterclockwise and streak the remaining area about 6-8 streaks four-way streak method is a simple & ;! Not streak from the agar medium 29 ; 14 ( 23 ):5085. doi: 10.3390/nu14235085 smearing of of!, some prefer to make the final streak in a radial direction up to the far edge of streak... Half of the following common errors in pour plating isolate bacteria from a mixed bacterial was. Logo are registered trademarks of the petri plate, divide the plate into thirds with your wax marker and as! Colonies over solid media, the smear is successively streaked over the agar.! The form of suspension, properly mix the suspension before taking inoculum to plate a sample... Technique would you use in the following situations counting method employed to plate a liquid to., liquid broth, or colonies over solid media at one edge of plate! Isolate bacteria from a mixed bacterial culture was not adequately diluted bacterial culture not.

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