A 50 mL sample of soup was found to be contaminated with E. coli. A dilution of the soup was prepared by adding 14 mL of the soup to 20 mL of water. This was then diluted 1/60, and finally 10-3. Duplicate plates of the final dilution were prepared and after incubation, CFUs recorded as follows: Volume plated (mL) CFUs recorded 1.0 TNTC 305 0.25 72 65 0.1 27 29 Determine the concentration of E. coli in the original soup sample.
. A 50 mL sample of soup was found to be contaminated with E. coli. A dilution of the soup was prepared by adding 14 mL of the soup to 20 mL of water. This was then diluted 1/60, and finally 10-3. Duplicate plates of the final dilution were prepared and after incubation, CFUs recorded as follows:
Volume plated (mL) CFUs recorded
1.0 TNTC 305
0.25 72 65
0.1 27 29
Determine the concentration of E. coli in the original soup sample.
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