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A pour plate is an alternative method for using agar plates to obtain isolated colonies. Pour plates are used when it is necessary to know the number of organisms present per unit volume of specimen or other sample. When a specific aliquot is placed in the Petri dish, a count of the colonies that grow after incubation reveals their concentration in the original sample. Pour plates are used commonly in the bacteriologic examination of milk, or could also be used to determine whether sufficient bacterial numbers are present in urine samples to signify the patient has a urinary tract infection. The number of bacteria in solution can be readily quantified by using the spread plate technique. In this technique, the sample is appropriately diluted and a small aliquot transferred to an agar plate. The bacteria are then distributed evenly over the surface by a special streaking technique. After colonies are grown, they are counted and the number of bacteria in the original sample calculated. Streaking in this technique is done using a bent glass rod. 0.1 mL of bacterial suspension is placed in the center of the plate using a sterile pipet. The glass rod is sterilized by first dipping it into a 70% alcohol solution and then passing it quickly through the Bunsen burner flame. The burning alcohol sterilizes the rod at a cooler temperature than holding the rod in the burner flame thus reducing the chance of you burning your fingers. When all the alcohol has burned off and the rod has air-cooled, streak the rod back and forth across the plate working up and down several times. Unlike streaking for isolation, you want to backtrack many times in order to distribute the bacteria as evenly as possible. Turn the plate 90 degrees and repeat the side to side, up and down streaking. Turn the plate 45 degrees and streak a third time. Do not sterilize the glass rod between plate turnings. Cover the plate and wait several minutes before turning it upside down for incubation. This will allow the broth to soak into the plate so the bacteria won't drip onto the plate lid.

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What is the main advantage of pour-plate method over other methods of bacterial colony isolation?

Previous answer: "because of infection" This person is obviously trying to be funny, the right word should be "Contamination", as for spread plate, the bacteria is more exposed to air as it is spread over the agar plate. Therefore, the result might not be accurate, as it might be contaminated. As for the pour plate method, the bacteria is in the agar itself, it is not exposed to air, thus, less risk of getting contaminated.


What is the disadvantage of pour plate techniques?

One disadvantage of pour plates is that the embedded colonies will be much smaller than those which happen to be on the surface and must be carefully scored so that none are overlooked, also obligate aerobes may grow poorly if embedded in agar


What is the purpose for pour plate?

The purpose of a pour plate is to determine the concentration of bacteria in a sample by counting the number of colonies that grow on the agar plate after incubation. This method allows for both surface and subsurface colonies to be counted, providing a more accurate representation of the bacterial population in the sample.


What are the surface colonies on a pour plate larger than those within the medium?

The surface colonies on a pour plate larger than those within the medium especially aerobic bacteria within the medium would be a restriction of growth. The restriction of growth would be due to the lack of oxygen.


What are 3 methods used to isolate microorganisms from a mixed culture?

It is necessary to make the colonies well-isolated from each other so that each appears distinct, large and shows characteristic growth forms.Most bacteria, many other microfungi, and unicellular microalgae, may be most commonly obtained by plating methods such as streak plate method, pour plate method and spread plate method.

Related Questions

How do the results of pour plate method compare with those obtained using the streak plate and spread plate method?

In the pour plate, the microorganisms will grow within the gel that has been set, and in the spread-plate technique, growth will be on top of the agar gel where it has been spread.


Do both the spread-plate and pour-plate method in a experiment produce similar bacterial counts or are they vastly different?

Both Spread-plate and pour plate method don't give the same results. Because in the case of spread plate method the inoculmn used for inoculation can't be spread in a exact volume. A little inoculmn remains stick with the spreader after spreading. On the other hand, in pour plate method it doesn't happen. So mostly, through comparing the counts by both methods, less counts are obtained in spread plate method. I am Working as a Sr. Microbiologist in a Biotech company


How does the contribution of growth on a pour plate different from that on a steak plate?

Colonies growing on a pour plate have slightly less avalible oxygen and are confined by the gel matrix so they tend to grow smaller than those on a pour plate. Streak plates are use to isolate single colonies, pour plates are used to enumerate batceria.


How do colonies on the surface of a pour plate differ from those suspended in agar?

How do colonies on the surface of a pour plate differ from those suspended in the agar?


What is the main advantage of pour-plate method over other methods of bacterial colony isolation?

Previous answer: "because of infection" This person is obviously trying to be funny, the right word should be "Contamination", as for spread plate, the bacteria is more exposed to air as it is spread over the agar plate. Therefore, the result might not be accurate, as it might be contaminated. As for the pour plate method, the bacteria is in the agar itself, it is not exposed to air, thus, less risk of getting contaminated.


What is the disadvantage of pour plate techniques?

One disadvantage of pour plates is that the embedded colonies will be much smaller than those which happen to be on the surface and must be carefully scored so that none are overlooked, also obligate aerobes may grow poorly if embedded in agar


Could some bacteria grow on the streak plate and not be seen using the pour plate technique?

Put simply - yes. Some strictly aerobic organisms will not grow in a pour plate. They may, however proliferate on a streak plate. Also consider the posibility of experimental error. The culture may have been added to the molten agar when it was too hot for the organisms to survive.


What are the Different methods used to isolate microorganisms?

1 The Spread Plate: If a mixture of cells is spread out on an agar surface so that every cell grows into a completely separate colony, a macroscopically visible growth or cluster of microorganisms on a solid medium, each colony represents a pure culture. The spread plate is an easy, direct way of achieving this 2 The Pour Plate: Extensively used with bacteria and fungi, a pour plate also can yield isolated colonies. The original sample is diluted several times to reduce the microbial population sufficiently to obtain separate colonies when plating result. 3 The streak plate: Pure colonies also can be obtained from streak plates. The microbial mixture is transferred to the edge of an agar plate with an inoculating loop or swab and then streaked out over the surface in several patterns


Does the streak plate method work better than the pour plate method?

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How to determine Bacterial load?

By pour plate and then counting the colonies.


If a sauce is provided on your plate in a gravy dish can you dip your food in it or do you have to pour it on your food?

This is entirely up to you, but it is expected that you pour it.


Which method often results in colonies developing down throughout the agar and some colonies on the surface?

The pour plate method often results in colonies developing both down throughout the agar and on the surface. This is because the pour plate involves mixing the bacteria with the agar before pouring it into the plate, allowing for colonies to form at different depths within the agar.