Chicken Wing Microbiology

Abstract:: In the first week of this three-lab series, students wash store-bought chicken wings in sterile saline, serially dilute the resulting bacterial suspension, and inoculate agar plates. In the following week, students count the colonies and calculate the number of colony-forming units per ml of wash fluid (typically around 10^6 cfu/ml). They design experiments to test treatments that might reduce the microbial contamination of chicken wings, and they collect the data during the third week. Instructor notes include safety reminders, suggestions for incubating plates, and ideas for possible assignments.

Read the Fine Print

Serial Dilution of Food Coloring Dye

Abstract:: Students use dyes to explore serial dilution, an important technique in physical science and engineering. Students systematically dilute solutions of food coloring with pure water. They observe how the color intensity, or saturation, of each subsequent solution changes. They also keep a running calculation of the concentration of drops per ml water. They apply what they learn to discussions of biomedical engineers working with cells.

Read the Fine Print

Abstract:: Students explore serial dilution, an important technique in physical science and engineering. They use a fluorescent compound as the dye to track through a series of dilution steps. They observe how the changing color intensity, or saturation, of each subsequent solution. They also keep a running calculation of the concentration dye in each serial dilution. Finally, using a UV lamp, they investigate whether the fluorescent dye can be detected after it disappears from view under normal lighting conditions.