Patent ID: 7449097

Claim:
An electrophoretic mobility measuring apparatus comprising: a cell capable of being filled with a sample, the cell including at least one cell wall; a transparent electrode forming a part of the at least one cell wall; an other electrode opposite to the transparent electrode; a voltage applying means for applying a voltage across both electrodes; a light incident unit for entering light into a region of the cell, wherein an electroosmotic flow substantially parallel to a face of the transparent electrode is generated through the transparent electrode; a light receiving unit for receiving, through the transparent electrode, outgoing light which scatters from the sample in the cell at a predetermined angle θ with respect to the incident angle; and a measuring unit for measuring the Doppler displacement of particles in the sample based on the difference in frequency between the incident light and the outgoing light, a direction of a scattering vector which is the vector difference between incident and outgoing vectors, being substantially identical with that of the normal line of the transparent electrode face.