What is the purpose of streak plates mark all that apply?
Streak plate technique is used for the isolation into a pure culture of the organisms (mostly bacteria), from a mixed population. The inoculum is streaked over the agar surface in such a way that it “thins out” the bacteria. Some individual bacterial cells are separated and well-spaced from each other.
What’s the basic steps of the streak plate method in the correct order from start to finish?
Procedure:
What is the purpose of a streak plate quizlet?
What is the purpose of streak plating? To obtain isolated, pure colonies. Bacteria is transferred to the edge of an agar plate with an inoculating loop and then treated out over the surface in one of several patterns.
What are some reasons for not getting isolated colonies from a streak plate?
Problem: The culture plate has colonies that do not look like most of the colonies, or there are colonies where nothing was streaked. Reason: The plate has become contaminated with bacteria or fungi from the environment.
What could account for the absence of growth on a streak plate?
Streak Plate ” should appear near or in a vaccinity of streak lines and sections. E9 ” What factor(s) could accunt for an absence of growth on a pour plate? The lack of oxygen, poor/ bad bacteria smear, or difference in temperature that prevents optimal growth, within media.
What does E coli look like on agar plate?
An E. coli colony is off-white or beige in color with a shiny texture. It often looks like mucus or a cloudy film over the whole surface of the plate.
What is the spread plate method?
The spread plate method is a technique to plate a liquid sample containing bacteria so that the bacteria are easy to count and isolate. Using a pipette, transfer a measured volume from a liquid sample containing bacteria and dispense it onto a fresh plate.
What is the difference between pour plate and spread plate method?
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.
What is the difference between streak plate and spread plate technique?
The key difference between streak plate and spread plate is that the streak plate is used to isolate and purify a particular bacterial species from a mixture of bacteria while the spread plate is used to enumerate and quantify bacteria in a sample.
What is the equipment needed to streak a plate?
From top to bottom, shown are toothpicks (flattened not round), a wire loop, a disposable plastic loop, and wooden sticks. Toothpicks are typically transferred to a small glass beaker with the wide end down then covered with foil when autoclaved to sterilize prior to use.
What advantages does the streak plate method have over the pour plate method?
What advantage does the streak plate method have over the pour-plate method? The streak plate method does not require any additional media for dilution and only requires one plate for inoculation.
What would a streak plate look like if you had not sterilized the loop between streaking into the new areas of the plate?
What would a streak plate look like if you had not sterilized the loop between streaking into the new areas of the plate? While the number of bacteria colonies seen in each area may decrease, the numbers would not decrease enough for individual colonies to form.
Which area of your streak plate will contain the greatest amount of growth?
The greatest amount will be found in the first quadrant because that has the highest content of mixture. The 4th quadrant will have the least amount, since it has the least amount of mixture. Does each discrete colony represent the growth of one cell?
Why do you sterilize the wire loop between streaking each quarter of the plate?
Flame the loop or use a new disposable loop after you streak each quadrant. Using a new or sterilized loop allows you to effectively dilute the inoculum on the plate and obtain isolated colonies by spreading the inoculum thinner and more evenly. 7.
When would you use the quadrant streak plate technique?
Micro Lab Quiz 1 Material ” Quadrant Streak Plate Technique
What is the first step in the five i’s?
What is the first step in the Five I’s? The purpose of an incubator is to recreate the proper growth conditions of a bacterial sample in order to promote bacterial growth. Media can be either selective or differential, but they cannot be both. Sabouraud’s agar is slightly acidic to aid in the growth of fungi.
What is T Streak method?
The three-phase streaking pattern, known as the T-Streak, is recommended for beginners. The streaking is done using a sterile tool, such as a cotton swab or commonly an inoculation loop. When the loop is cool, it is dipped into an inoculum such as a broth or patient specimen containing many species of bacteria.
How long do you hold the loop in the incinerator to sterilize it?
Place your loop in the mouth of the incinerator briefly for 2-4 seconds to sterilize it. Do not leave your loop in the incinerator for more than 10 seconds, you will destroy the loop!
Why do we flame the loop each time we transfer from one quadrant on the plate to the next?
Flaming the loop between streaks ensures that the loop starts clean and that only this small amount of bacteria is used to inoculate the next quadrant. This will draw too much bacteria into quadrant 4 and produce few, if any, isolated colonies.
Why is it important to cool an inoculating loop before touching it to a culture?
The inoculating loop must be cooled before it touches the surface of the medium. The loop must be cooled to prevent killing the bacteria. If the loop is too hot, it will kill the bacteria and sizzle and melt the media that further promotes contamination.
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