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Bacterial growth on agar plates
Moderators: AmyCowen, kgudger, MadelineB, Moderators
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602945
- Posts: 3
- Joined: Thu Jan 26, 2012 2:49 pm
- Occupation: student
- Project Question: My experiment compares the effectiveness of disinfecting water through boiling, to disinfected water using solar disinfection. I am required to use stream water and count the number of colonies at an interval of 24 hours. The water from the stream has so much bacteria that with 24 hours the agar plate is completely covered in bacteria. I need small colonies of bacteria for my experiment. How do I get countable colonies, not "lawns", to grow on the agar plates?
- Project Due Date: March 14, 2012
- Project Status: I am conducting my experiment
Bacterial growth on agar plates
My experiment compares the solar disinfection to boiling water to kill bacteria. I am required to grow bacteria on agar plates and count the colonies of bacteria to compare the effectiveness of the two disinfection methods, but when I tried to grow bacteria I had so many bacteria that the entire plate was covered and I could not count any colonies. How do I growth countable bacteria colonies? Would a subculture system using the streak method be effective? I appreciate the help!
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deleted-63393
- Posts: 45
- Joined: Tue Jan 10, 2012 6:16 pm
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Re: Bacterial growth on agar plates
You are going to want to dilute your bacterial sample. You can do this using LB (luria broth) media or sterile water. Here is a short procedure I found on google to help you out. http://www.waksmanfoundation.org/labs/r ... lution.htm
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602945
- Posts: 3
- Joined: Thu Jan 26, 2012 2:49 pm
- Occupation: student
- Project Question: My experiment compares the effectiveness of disinfecting water through boiling, to disinfected water using solar disinfection. I am required to use stream water and count the number of colonies at an interval of 24 hours. The water from the stream has so much bacteria that with 24 hours the agar plate is completely covered in bacteria. I need small colonies of bacteria for my experiment. How do I get countable colonies, not "lawns", to grow on the agar plates?
- Project Due Date: March 14, 2012
- Project Status: I am conducting my experiment
Re: Bacterial growth on agar plates
Originally my bacteria sample was collected from a creek. Do I need to add distilled water to this sample to dilute the sample?
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deleted-71536
- Former Expert
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- Project Question: How do different animals adapt to their environment?
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Re: Bacterial growth on agar plates
Hi there,
You could dilute your initial sample, or dilute the experimental samples prior to plating. Either way, sterile water would be appropriate.
Let us know if you have further questions!
Heather
You could dilute your initial sample, or dilute the experimental samples prior to plating. Either way, sterile water would be appropriate.
Let us know if you have further questions!
Heather
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602945
- Posts: 3
- Joined: Thu Jan 26, 2012 2:49 pm
- Occupation: student
- Project Question: My experiment compares the effectiveness of disinfecting water through boiling, to disinfected water using solar disinfection. I am required to use stream water and count the number of colonies at an interval of 24 hours. The water from the stream has so much bacteria that with 24 hours the agar plate is completely covered in bacteria. I need small colonies of bacteria for my experiment. How do I get countable colonies, not "lawns", to grow on the agar plates?
- Project Due Date: March 14, 2012
- Project Status: I am conducting my experiment
Re: Bacterial growth on agar plates
Thank you for all the help.