Question #006f1

1 Answer
Sep 9, 2016

Plate out a known volume on the correct media, and grow. Count the colonies.

Explanation:

Example calculation:

Plate out 50 µl
Counted colonies - 75

The 75 colonies come from 50 µl, hence in 1 ml there would be:

75 x 20 colonies (there are 20 lots of 50 µl in 1 ml) = 1,500

However, there was a 1 in 10 dilution at the start, so in total there would be 1,500 x 10 = 15,000 CFU/ml.