Identification of Unknown Proteins Using Three Forms of Polyacrylamide Gel Electrophoresis

A laboratory experiment involving a comparison between various forms of polyacrylamide gel electrophoresis (native, reducing and non-reducing sodium dodecyl sulfate) was performed in an undergraduate biochemistry laboratory. Students executed one form of electrophoresis, and analyzed the same seven unknown samples using both fixed (10%) and gradient (4–20%) polyacrylamide gels. Based on the key protein properties of sixteen unknowns, together with the combined student results and focus questions that guided interpretation of gel data, students identified the unknown protein samples and gained valuable experience on each form of electrophoresis, while contrasting fixed and gradient polyacrylamide gel separations.