Table of Contents

• Section 1. How to Do a Viable Plate Count
• 1: Why we need to dilute
• 2: Setting the stage: Diluting Cold Press Coffee
• 3: Working out the dilution
• 4: Overall dilution
• 5: Design a dilution!
• 6: How to scale back up
• 7: Count a plate!
• 8: Why plate more than one dilution?
• 9: Picking the plate to count
• Section 2. Practice Problems
• 10: Putting it all together
• 11: Quickies
• 12: Is the water safe?
• Section 3. Review
• 13: Summary

Summary

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

If you want a printer-friendly version of this module, you can find it here in a Microsoft Word 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.