Demonstrating core molecular biology principles using GST-GFP in a semester-long laboratory course

Undergraduate laboratory courses are essential to teaching core principles in STEM. This course, Quantitative Biological Methods, provides a unique approach to teaching molecular biology research techniques to students, in a laboratory that is delivered in a sequence that parallels standard biomedical research laboratory protocols. Students attend a lecture where they are taught the essential principles of biomedical research, and a lab where they learn to use laboratory equipment, perform experiments, and purify and quantify DNA and proteins. The course begins with an introduction to laboratory safety, pipetting, centrifugation, spectrophotometry, and other basic laboratory techniques. Next, the lab focuses on the purification and analysis of glutathione S-transferase (GST) fused to green fluorescent protein (GFP) from an Escherichia coli lysate. Students study this GST-GFP fusion protein and perform protein quantification, enzyme assays, chromatography, fluorescent detection, normalization, SDS-PAGE, and western blotting. Students then learn recombinant DNA technology using the GST-GFP vector that was the source of the fusion protein in the prior labs, and perform ligation, transformation of E. coli cells, blue/white screening, DNA purification via a miniprep, PCR, DNA quantification, restriction enzyme digestion, and agarose gel electrophoresis. Students write laboratory reports to demonstrate an understanding of the principles of the laboratory methods, and they must present and critically analyze their data. The lab methods described herein aim to emphasize the core molecular biology principles and techniques, prepare students for work in a biomedical research laboratory, and introduce students to both GST and GFP, two versatile laboratory proteins.