Resumen de Candies to Dye for:: Cooperative, Open-Ended Student Activities to Promote Understanding of Electrophoretic Fractionation

Robert Curtright, Randall Emry, Jonathan A. Wright, John P. Markwell

• A three-part series of laboratory activities is presented that allows students to learn why electrophoretic separations work and to manipulate the factors that influence the separation process. In the first two exercises, students perform cooperative separations of FDandC dyes from candies utilizing electrophoresis in two buffers of different pH. Students must use package information from one brand of candy and critical thinking to determine the identities of these dyes. Using structural formulas for the dyes the students draw conclusions regarding the effect of charge and molecular mass on separation. The final activity is an open-ended investigation into a student-formulated question. These activities integrate topics in biology and chemistry into activities that interest students and foster a real understanding of the tool of electrophoresis.