Enter the dilution factor and the number of colonies into the calculator to determine the concentration of bacteria in a sample as colony-forming units per milliliter (CFU/mL).
CFU/mL Formula
The following formula is used to calculate the CFU/mL.
CFU/mL = N * D
Variables:
- CFU/mL is the concentration of bacteria in a sample (colony-forming units per milliliter)
- N is the number of colonies counted
- D is the dilution factor
To calculate CFU/mL, multiply the number of colonies counted by the dilution factor.
What is CFU/mL?
CFU/mL stands for colony-forming units per milliliter and is a measure of the number of viable bacteria or fungal cells in a sample. It is a common unit used in microbiology to estimate the concentration of microorganisms in a liquid culture. The CFU/mL value helps in understanding the level of contamination or the efficiency of bacterial growth under various conditions.
How to Calculate CFU/mL?
The following steps outline how to calculate the CFU/mL.
- First, determine the number of colonies counted (N).
- Next, determine the dilution factor (D).
- Use the formula CFU/mL = N * D.
- Finally, calculate the CFU/mL.
- After inserting the variables and calculating the result, check your answer with the calculator above.
Example Problem :
Use the following variables as an example problem to test your knowledge.
number of colonies counted (N) = 50
dilution factor (D) = 10^3
