Laser Doppler electrophoresis using a diffusion barrier

In one aspect, it comprises providing a container holding the dispersing agent, comprising: providing a first electrode immersed in the dispersant, and providing a second electrode immersed in the dispersant, electrophoresis measurement method is disclosed. Samples in position within the dispersing agent between the first electrode and the second electrode are arranged in a state of being separated from the electrodes, an AC electric field across the first electrode and the second electrode is applied, the sample is temporally It is illuminated with coherent light. It has interacted with the sample during the process of applying an alternating electric field, in the light from the irradiating, detecting a frequency shift. Then, based on the results of the step of detecting the characteristics of the sample is derived.