Full text get a printable copy pdf file of the complete article 209k, or click on a page image below to browse page by page. Agar plates were incubated at 37 c for 24 h before counting, and then photographed. The pour plate method of counting bacteria is more precise than the streak plate method, but, on the average, it will. Jun 04, 2018 the main difference between pour plate and spread plate is that the molten agar is poured on to the inoculum during the preparation of the pour plate whereas inoculum is spread on the surface of the solidified agar during the preparation of the spread plate. The following methods are used to isolate pure culture.
Firstly, users will not be able to grow obligate anaerobes using this method. The pour plate method of counting bacteria is more precise than the streak plate. Explain advantages and disadvantages of spread plate method. The main difference between streak plate and pour plate is that in streak plate, the first to be added is the melted nutrient agar and the second to be added is a loop of bacteria from a slant, whereas the first to be added in pour plate is the bacterial broth and the second to be added is the nutrient agar. The dilution or isolation by streaking method was first developed by loeffler and gaffky in kochs laboratory, which. It is essentially a dilution technique that involves spreading a loopful of culture over the surface of an agar plate. Each method has advantages and disadvantages, and particular uses. Cleverdon department of bacteriology, university of connecticut, storrs, connecticut abstract a comparison was made of agar plates spread with glass rods and poured agar plates for the enumeration of bacteria in the waters of fishers island. Colonies that differ in appearance are typically different bacterial strains, species, or genera.
May 08, 2019 what are the disadvantages using streak plate method. Jul 09, 2014 what are advantages and disadvantages of pour and spread plates. Apr 02, 2011 the advantage of the spread plate over the pour plate is duh. Dear all, im just wondering which method you guys are applying in your companies. Streak plate method advantages and disadvantages advantages. Advantages and disadvantages method advantages disadvantages. The plate count method or spread plate relies on bacteria growing a colony on a nutrient medium. Hasslefree, convenient, usually you will be able to get a few visible individual colonies in just one plate if your streaking skills are good. Prior to sampling, calibrate your pump to 15 liters per minute via a rotameter. In the pour plate technique, diluent containing the sample typically 1 ml is added to a sterile petri dish. Streak plate 11 pour plate 12 using a spreader spread plate 14. Full text get a printable copy pdf file of the complete article 364k, or click on a page image below to browse page by page. Streak plate technique for isolation of microorganism. Two dilutions 106 and 10 of the peat inoculant were plated in quadruplicate and incubated at 28c for 7 days.
Furthermore, the volume of inoculum in the streak plate is only a. Streak plate technique is used for the isolation into a pure culture of the. Loop is flamed to kill any potentially contaminating bacteria before inoculation. What is a disadvantage of the streak plate technique. Generally the dilution factor at each step is constant. Dear aunt yersinia, what are advantages and disadvantages of pour and spread plates. Streak plate method principle, methods, significance.
Like the wet mount, the hanging drop method preserves cell shape and arrangement. The pour plate method of counting bacteria is more precise than the streak plate method, but, on the average, it will give a lower count. Some individual bacterial cells are separated and well spaced from each other. Streak plate method principle, methods, significance, limitations. A disadvantage of the streak plate technique could be colony isolation problems. Of these the surface spread plate method is now widely used in europe and is. A comparison was made of agar plates spread with glass rods and poured agar plates for the enumeration of bacteria in the waters of fishers island sound, salinity 30. Micro students may find this presentation on culture methods useful slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. Interpretation method of microbial identification test things to do. Streak plate, spread plate and pour plate what is the steak plate technique for isolation. It can used only for obtaining isolated colonies in pure culture. A loop is used to streak the mixed sample many times over the surface of a solid culture medium in a petri plate.
The streak plate isolation method as described on the steps mentioned above. Other disadvantages are the reduced growth rate of. Thepourplate methodofcountingbacteria is moreprecise than the streak plate method, but, onthe average, it will give alower count. The spread plate technique involves using a sterilized spreader with a smooth surface made of metal or glass to apply a small amount of bacteria. So what advantages are there for one method over the other. The spread plate technique involves using a sterilized spreader with a smooth surface made of metal or glass to. Preparation for the pour plate method is time consuming compared with streak plateand or spread plate technique.
Ptak and ginsburg12 also listed these advantages for the streak plate method and showed that for the same samples. Isolation of bacteria by dilution techniques flashcards. Isolation of bacterial colonies using the quadrant method the streak plate procedure is designed to isolate pure cultures of bacteria, or colonies, from mixed populations. If the streaking technique is not done properly or if there is too much of an organism present on the inoculating. To report and interpret observation of identification tests tests have been. Two different types of agar plate isolation techniques will be usedstreak and pour. Disadvantages fungi cannot be identified to species with this method. One advantage of using beads instead of a spreader is that no open containers. Successful streaks lead to individual colonies of microbes.
Advantages and disadvantages of serial dilution method. Streak plate technique streaking is the process of spreading the microbial culture with an inoculating needle on the surface of the media. Isolate single bacterial colonies by the streakplating method. The colony becomes visible to the naked eye and the number of colonies on a plate can be counted. Secondly, only organisms that were viable in the original sample are able to be grown. Loop is flamed to kill any potentially contaminating bacteria. Know other methods described in the manual, text or class to achieve isolation besides the streak plate method and their advantages and disadvantages when compared to the streak plate method. Samples can then be taken from the resulting colonies and a microbiological culture can be grown on a new plate so that the organism can be identified, studied, or tested. The initial inoculum is placed in the top half of the plate.
I am a qa analyst in a biscuit company and have been having a hard time deciding which method to use to verify the microbiological level of our finished products. Thats certainly one way of quantifying the population. From these mixed colonies, single bacterial or fungal species can be identified based on their morphological sizeshapecolour differences, and. Loss of viability of heatsensitive organisms coming into contact with hot agar. Method of isolation of pure culture linkedin slideshare.
Advantages and disadvantages of serial dilution method ask for details. This allows for individual colonies to be isolated from other colonies. Colony streaking leads to to the isolation of individual. Spread plate technique is the method of isolation and enumeration of microorganisms in a mixed culture and distributing it evenly. What is the difference between streak plate and pour plate. The spread plate is designed to create a lawn of the microbe evenly across the plate. Most microbiologists repeat streaking from an isolated colony two to three times before they guarantee culture purity.
By using a differential medium one can also make a presumptive identification of. Streak plate method of isolation purpose the streak plate technique is the most widely used method of obtaining isolated colonies from a mix of cultures. What are two advantages of the streak plate technique. Spread plate technique methods of isolating pure culture 3. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Streak plate technique is used for the isolation into pure culture of the organisms mostly bacteria, from mixed population. While all molecular biologists know or have at least seen a spread plate aka petri dish with some agar in it, a pour plate is quite exotic. Bacterial colony morphology and identification of bacteria. This method is used for isolating the discrete colonies of the microorganism. Due to the similarities in spore morphology, some spores will be grouped together, i. The main difference between pour plate and spread plate is that the molten agar is poured on to the inoculum during the preparation of the pour plate whereas inoculum is spread on the surface of the solidified agar during the preparation of the spread plate. The serial dilution method is utilized to decline the number of microorganism in the inoculum. Streak plate method is utilized for the qualitative isolation of the microorganism.
Aug 15, 2019 spread plate technique is the method of isolation and enumeration of microorganisms in a mixed culture and distributing it evenly. Streak plate methods vary by the number of agar sections streaked. Principle, procedure, applications, advantages, limitations of spread plate technique. Ofthe three methods, the drop plate procedure was the most preferable because more countscouldbemadeononeplate fig.
The vaselinesealed depression also slows down the dryingout process, so the organisms can be observed for longer periods. At the end of incubation there should be enough bacteria to form visible colonies in the areas touched by the inoculation loop. The number of viable microorganisms in a sample can be counted by using the pour plate method or the spread plate method. The spread plate as a method for the enumeration of marine bacteria john d. Embedded colonies are much smaller than those which happen to be on the surface. Overview of pour plate method and spread plate method. It is the ideal method if you are doing general work with a certain type of microorganism.
The inoculum is streaked over the agar surface in such a way that it thins out the bacteria. A comparison of pour plate and spread plate methods. The technique makes it easier to quantify bacteria in a solution. What is the advantages of streak plate method answers. A comparison was made of agar plates spread with glass rods and poured agar plates for the enumeration of bacteria in the waters of fishers island. Principle the streak plate technique is essentially a method to dilute the number of organisms, decreasing the density.
Streak plating is a method that allows microorganisms to be grown from a sample on an agar plate. However, colony morphology is not a reliable way to identify bacteria, as many different types of bacteria have similar colony morphology. Disadvantage of the streak plate technique answers. Preparation for pour plate method is time consuming compared with streak plate and or spread plate technique. Spread plate technique principle, procedure, advantages. To pour or to spread, this is the question bitesize bio. Principles of differential, enriched and selective media, and various biochemical tests 3. What are the disadvantages of the streak plate method. The spread plate seems to be your method of choice when compared with the mpn for any application with the following exceptions.
Antonio it is refreshing to see such wisdom knowing that there are at least two methods of pouring plates in a young man. Pour plate technique procedure, advantages, limitations. Nov 25, 2017 the following methods are used to isolate pure culture. Basic practical microbiology a manual by society for general microbiology sgm. The hanging drop method is also far too risky to use with highly pathogenic organisms.
The streak plate method is a rapid qualitative isolation method. It helps to reduce a dense culture of cells to a more usable concentration. Pour plates are usually the method of choice for counting the number of colonyforming bacteria in fluids 1. Back in the lab, you put a sample on a slide under a microscope, and counted everything that looked like a. Isolation of bacteria by dilution techniques flashcards quizlet. What are the disadvantages using streak plate method. What advantage does the streakplate method have over the.
Inoculum refers to microorganisms, bacteria or fungi that grow in or on the nutrient agar. Bacteria are dragged from the top section to one of the bottom sections, then from that bottom section to the other. To be effective, the dilution of the original sample must be arranged so that on average between 30 and 300 colonies of the target bacterium are grown. The techniques commonly used for isolation of discrete colonies initially require that the number of organisms in the inoculums be reduced.
Oct 03, 2009 at the end of incubation there should be enough bacteria to form visible colonies in the areas touched by the inoculation loop. In microbiology, streaking is a technique used to isolate a pure strain from a single species of microorganism, often bacteria. Aseptic technique, dilution, streaking, and spread. Aseptic technique is basically the mindset of keeping things free of contamination, as the world we live in has so many microbes that can interfere with experiments. In this technique, a serially diluted specimen containing 2 or more bacteria or microbe mixed culture is used which is spread over the solidified agar media plates as a thin layer with the help of a sterile lshape glass rod spreader while the media plate is spun on a turntable. Home basic microbiology streak plate method principle, methods, significance, limitations. The streak plate method enables you to select and work with individual colonies. Difference between pour plate and spread plate pediaa. What is the advantage of viable count method over the. Microbiologists rely on aseptic technique, dilution, colony streaking and spread plates for daytoday experiments. Get a printable copy pdf file of the complete article 209k, or click on a. Spread plate technique principle, procedure and uses. The streak plate culture technique for the isolation of microorganism is the most practical method of obtaining discrete and welldeveloped colonies of the microbe in pure cultures. The term colony morphology refers to the visible characteristics of a colony.
Comparison of the pour, spread, and drop plate methods for. Advantages and disadvantages of streak, spread and pour. By streak plate method one can isolate a bacterial strain, from a mixed culture, in pure form as colony. Principle, procedure, uses, and dis advantagesoctober 16. The serial dilution method involves a stepwise dilution of a. The drop plate method was preferred because of its economy in materials and labor. If you continue browsing the site, you agree to the use of cookies on this website. When you have a streak plate, your endgoal is to isolate individual colonies of your microbe. Jan 14, 2020 streak plate method advantages and disadvantages advantages. Comparison pour, spread, plate methods enumeration of. Streak plating is a microbiology laboratory method that has two major disadvantages. What are the disadvantages using streak plate method answers. Samples can then be taken from the resulting colonies and a microbiological culture can be grown on a new plate so that the organism can be identified, studied, or tested the modern streak plate method has progressed from the efforts of robert. Streak plate method cannot be used for the enumeration of the approximate number of bacteria in the given sample.
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