Electrophoresis on a chip increasingly replaces electrophoresis in the capillary format because of its speed and containment of the sample within a disposable cartridge. In this paper we demonstrate its utility in the analysis of the interaction between a virus and a liposome-anchored receptor, mimicking viral attachment to host cells. This became possible because detergents, obligatory constituents of the BGE for capillary electrophoretic separation of the virus, were not necessary in the chip format. Separations were carried out in sodium borate buffer, pH 8.3. Liposomes and virus were both labeled for laser-induced fluorescence detection at lambda(ex)/lambda(em) 630/680 nm. Free virus and virus-receptor complexes were resolved from virus attached to receptor-decorated liposomes in the absence of additives or sieving matrices within about 30 s on commercially available microfluidic chips.