Make sure you understand the following concepts — go back to the applets if you need to:

**dilution**(stated as a fraction or in scientific notation)**overall dilution**(product of individual dilutions)**choosing the plate**to count (30 to 300 CFUs)**scaling up from the plate**to the population size (multiplying by the dilution factor)**setting up an appropriate dilution scheme**to result in a countable plate

## Learning Outcomes

Now you have completed this module, you should be able to:

- Define dilution and dilution factor
- Explain why dilutions are necessary for microbial counts
- Prepare dilutions and calculate total dilution of serial dilutions
- Set up an appropriate dilution scheme to result in a countable plate
- Evaluate and interpret the results of plate counts, including selecting the appropriate plate for counting and scaling up from the diluted sample to the original population

*If you want a printer-friendly version of this module, you can find it here in a PDF document. This printer-friendly version should be used only to review, as it does not contain any of the interactive material, and only a skeletal version of problems solved in the module.*