Enter the number of colonies, dilution factor, and volume of culture into the calculator to determine the colony-forming units per gram (CFU/g) of a sample.
Cfu/G Formula
The following formula is used to calculate the CFU/g.
CFU/g = (Number of Colonies * Dilution Factor) / Volume of Culture (ml)
Variables:
- CFU/g is the colony-forming units per gram
- Number of Colonies is the count of colonies observed on a plate
- Dilution Factor is the factor by which the original sample was diluted
- Volume of Culture is the volume of the diluted sample plated (in milliliters)
To calculate CFU/g, multiply the number of colonies by the dilution factor, then divide by the volume of the culture plated. This will give you the concentration of viable bacteria or fungi in the original sample per gram.
What is CFU/g?
CFU/g stands for colony-forming units per gram and is a measure of the viable bacterial or fungal numbers in a sample. It is commonly used in microbiology to estimate the number of viable microorganisms in a sample and is important for assessing the safety and quality of food products, as well as the microbial load in environmental samples.
How to Calculate CFU/g?
The following steps outline how to calculate the CFU/g.
- First, count the number of colonies that grew on the agar plate.
- Next, determine the dilution factor used when preparing the sample.
- Next, measure the volume of the culture that was plated (in milliliters).
- Use the formula CFU/g = (Number of Colonies * Dilution Factor) / Volume of Culture (ml) to calculate the CFU/g.
- 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 = 250
Dilution Factor = 10^3
Volume of Culture (ml) = 1
