Non-resolved electropherogram of mixture QD-hydrazide (1) and whole antibody-conjugated QDs (QD-IgG) (2). Sharp peaks (3) observed at the migration time of QD-IgG are attributed to buffer additive (BSA) cross-reacting with the antigen-binding site of the IgG. IgG used for conjugation was rabbit anti-human albumin. CE buffer electrolyte used was 50 mM borate (pH 9.2), 0.1% BSA. Gravity injection performed by elevating inlet capillary 7 cm for 5 s. Applied voltage for CE separation was 25 kV. Capillary temperature maintained at 20°C. Excitation source and detection wavelength was 473 nm and 620 nm, respectively.