Abstract: A micro-video imaging system on-line coupled with UV detection and capillary electrophoresis has been set up and used for the investigation of human red blood cells(hRBC). Both free and aggregated cells were observed via the imaging and the broad peak overlain by bar-like peaks measured from UV detection was shown responsible for the free migrated and aggregated cells, respectively. More importantly, fast measurement of cell mobility was achieved within one second using the image acquired and the calculated mobility data agreed with that of UV, giving a deviation of less than 7%. Further more, this micro-video system allows us to vividly observe the adsorption-desorption process. In a fused-silica capillary, about 10% of the human red blood cells were turned out to adsorb on the tubing surface, they left the surface after 0.04 s to 3.12 s, giving an average retarding time of less than 1 s. This causes a loss of migration mobility of 5×10^-6 cm²·V^-1·s^-1. It was thought that this system be applicable to the study of adsorption of other types of molecules with some modification.

Key words: Capillary electrophoresis, Image, Red blood cell, Migration, Adsorption