What is the disadvantage of the streak plate technique?
What is the disadvantage of the streak plate technique?
What is a disadvantage of the streak plate technique? You can’t accurately count how many colonies there are. What is a disadvantage of the pour plate technique? Sometimes bacteria will clump together and look like a colony when they are not. Will the isolated colonies always be in the fourth sector on the streak plate …
What are the steps in the streak plate method?
Procedure for Streaking a Plate for Isolation:
- Flame the loop and wire and streak a loopful of broth as at A in the diagram.
- Reflame the loop and cool it.
- Streak as at B to spread the original inoculum over more of the agar.
- Reflame the loop and cool it.
- Streak as at C.
- Reflame the loop and cool it.
- Streak as at D.
What are the advantages of streak plate method?
Advantages
- The streak plate method enables you to select and work with individual colonies.
- It is the ideal method if you are doing general work with a certain type of microorganism.
How long does it take for bacteria to grow on agar plate?
4-6 days
Why does bacteria grow on agar plates?
Agar is a compound that is derived from algae. It contains many nutrients, and bacteria can thrive on it. After this liquid is poured into sterile Petri dishes, it solidifies into a gel and can be used as a medium for bacterial growth.
Why are agar plates incubated at 37 degrees?
Optimal Growth Conditions Thus, a microbiologist will incubate a particular strain of bacteria at its optimal temperature so that he can study it when it is healthy. Organisms that grow best at human body temperature, which is approximately 37 degrees Celsius (98.6 degrees Fahrenheit), are called mesophiles.
Why are agar plates incubated at 30 degrees?
Do not incubate at human body temperature (or above 30 °C) – this reduces the risk of culturing microbes that are pathogens to humans. 5 Plates are incubated upside down (agar up), so that condensation does not drip onto the plate and interfere with the developing microbes.
What temperature do you incubate agar plates?
32° C
Why is it important to label the bottom of the agar plate the side with the agar and not the lid of the plate?
After the culture medium is set, and streaked with the required microbe/stock, the lid is put on and the petri dish is incubated upside down to minimize contamination. So, it is easier to read the label on the bottom. agar plates must be kept with lid on to avoid contamination when not being used.
Why are you instructed to write only on the back of the plate and never on the lid?
Why were you instructed to write only on the back of the plate & never on the lid? Because the lid could fall or it could move causing the marks to get moved to the wrong place & data would be messed up. Also agar isn’t on the lid, nothing will grow.
Why are agar plates always labeled at the bottom?
The lid of Petri dishes may contain any contamination that spreads on the media and grows with the sample microbes. We label the Petri dishes at the bottom part because lid may exchange with other Petri dishes creating confusion and inverted position makes it easy to read the labeling of Petriplates.
Do agar plates need to be refrigerated?
All agar on plates (Petri dishes) should be stored refrigerated and should be used within one month after receiving. To prevent contamination, keep all bottles, tubes, and Petri dishes sealed until ready to use.
What does condensation do to agar plates?
If condensed water drips onto the agar, it can interfere with the growth of the colony of microorganisms. Depending on the type of experiment or study, it may be important to keep the colonies separate on a plate. Water on the agar has the potential to allow organisms to move across the plate into other areas.