The Diffusion Barrier Technique, practical aspects and data interpretation

Electrophoretic mobility is the rate of movement of a molecule or particle to an electrode in response to an applied electric field. Laser Doppler electrophoresis is commonly used to measure electrophoretic mobility. However, contact of the protein with the electrodes required for the application of the electric field is known to damage proteins and can cause them to denature and aggregate [3]. It is often erroneously thought that it is the electric field itself of a few volts per centimetre that causes the protein aggregation. In fact, it is contact of the proteins with the electrodes that causes the aggregation. Furthermore, capillary zone electrophoresis, a common technique used for the separation and characterisation of proteins, uses field strengths of hundreds of volts per centimetre and does not suffer a similar problem.