An experiment illustrating DNA-protein interactions using nuclear extracts from chicken erythrocytes

The electrophoretic mobility shift assay is a simple and rapid method for visualizing the existence of specific DNA-protein interactions and is a useful teaching experiment. In the experiment described here the students prepare nuclear extracts, a DNA probe, and can successfully produce specific DNA-protein complexes and estimate physicochemical parameters characterizing the interaction. The system described is easy to perform. The synthesis of the oligonucleotides required and the labeled deoxyribonucleotide used for labeling the probe are the main costs of the experiment, but since the synthesized oligonucleotides can be used in several courses and the amount of labeled deoxyribonucleotide required for labeling the probe is small the experiment is relatively inexpensive to put on with a class.