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Serial Dilutions

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You are given a milk sample that Mr. Milkman claims contains 3.8 x 10^8 CFU/ml. He claims this is within the limit of acceptable CFU/ml for Grade A milk. Diagram a procedure he could use to determine the CFU/ml and information pertinent to proving or disproving Mr. Milkman's claim. Is the milk within the acceptable limit?

You don't have to diagram it for me as long as you explain each step really well. Also, I know the milk is not within the acceptable limit i.e. 20,000 CFU/ml. I need the last dilution to get the colonies down to a countable number for someone to count on a plate. Maybe 38 colonies?

This process is demonstrated.

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If we start with 3.8x10^8 CFU/ml in the milk, then all we have to do is dilute it serially in order to end up with about 40 CFU/ml. Then all we have to do is plate 1 ml of the final dilution and we should have a nice number of around 40 colonies per plate to ...

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Serial Dilutions are featured.