Serial Dilution: Tracking Bacterial Population Size and Antibiotic Resistance
Serial dilution allows estimation of a range of bacterial population sizes. Percent resistance can be calculated by culturing bacteria on both antibiotic-free and antibiotic-containing media and comparing the results. In this Spreadsheet Across the Curriculum module, students explore the quantitative concepts of ratios and percentages and then apply those concepts to build Excel sheets that calculate bacterial population size and percent resistance.
Quantitive Goals: Students will develop a deeper and more explicit understanding of proportions, ratios, and populations of inference. They can also review scientific notation if necessary.
Spreadsheet Goals: Students will learn to use simple mathematical formulas in Excel. If they complete the optional appendix, they will also learn how to apply the IF and OR logical functions.
Biology (Content) Goals: Students will be able to calculate bacterial population size and percent resistance based on the number of colonies observed on agar plates after serial dilution.
Context for Use
Description and Teaching Materials
PowerPoint SSAC2006:QR67.AEW1.1-Student (PowerPoint 807kB Feb15 07)
If the embedded spreadsheets in the PowerPoint module are not visible, save the file to disk and open it from there.
This PowerPoint file is the student version of the module. An instructor version is available by request. The instructor version includes the completed spreadsheet. Send your request to Len Vacher (firstname.lastname@example.org) by filling out and submitting the Instructor Module Request Form (Acrobat (PDF) 91kB Aug20 12).
Teaching Notes and Tips
References and Resources
The Biological ESTEEM Collection -- a project of the BioQUEST Curriculum Consortium