Teaching Experimental Design Using an Exercise in Protein Fractionation

Abstract

This experiment, suitable for introductory biochemistry courses, presents the techniques of protein purification as a problem-solving exercise. Students must identify and purify three proteins from an unknown mixture using the techniques of gel filtration, ion exchange chromatography, UV and visible spectrophotometry, and gel electrophoresis. To aid construction of a strategy, they are given some information about each of the possible proteins: source, function, molecular weight, pI, and UV and visible spectra. From this they must design their own purification protocols and carry out the experimental work. To develop students' computer skills, the experimental results and the logic used in the identification are presented as a short computer-generated report.