Testing for total coliforms E coli in your water sample This series of tests

Testing for total coliforms e coli in your water

This preview shows page 2 - 3 out of 3 pages.

fermentation of lactose. Testing for total coliforms ( E. coli ) in your water sample: This series of tests has been used for the analysis of drinking-water for many years with satisfactory results. This is the only procedure that can be used if water samples are very turbid or if semi-solids such as sediments or sludges are to be analyzed. The procedure followed is fundamental to bacteriological analyses and the test is used in many countries. 1. Presumptive test - For initial testing of the presence of coliform bacteria in your water sample, you will serially dilute the water (see below) and add measured aliquots of the dilutions to lactose broths. Because coliforms are capable of fermenting lactose and other enteric organisms are not, the lactose media is ideal for detection of total coliforms. Following 24-hour incubation at 37C, the fermentation of lactose and the production of acid with associated color change from red to yellow will be presumptive evidence of the presence of coliform bacteria in your water sample. 2. Confirmed test - You will confirm that your water sample contains coliform bacteria by streaking a loopful of a positive lactose broth from the Presumptive test onto an Eosin Methylene Blue (EMB) plate. EMB is a selective and differential media that
Image of page 2
Image of page 3

You've reached the end of your free preview.

Want to read all 3 pages?

What students are saying

  • Left Quote Icon

    As a current student on this bumpy collegiate pathway, I stumbled upon Course Hero, where I can find study resources for nearly all my courses, get online help from tutors 24/7, and even share my old projects, papers, and lecture notes with other students.

    Student Picture

    Kiran Temple University Fox School of Business ‘17, Course Hero Intern

  • Left Quote Icon

    I cannot even describe how much Course Hero helped me this summer. It’s truly become something I can always rely on and help me. In the end, I was not only able to survive summer classes, but I was able to thrive thanks to Course Hero.

    Student Picture

    Dana University of Pennsylvania ‘17, Course Hero Intern

  • Left Quote Icon

    The ability to access any university’s resources through Course Hero proved invaluable in my case. I was behind on Tulane coursework and actually used UCLA’s materials to help me move forward and get everything together on time.

    Student Picture

    Jill Tulane University ‘16, Course Hero Intern

Stuck? We have tutors online 24/7 who can help you get unstuck.
A+ icon
Ask Expert Tutors You can ask You can ask You can ask (will expire )
Answers in as fast as 15 minutes
A+ icon
Ask Expert Tutors