A magnetic beads based immunoaffinity capillary electrophoresis method for total Immunoglobulin E quantification in serum has been developed. The method combines speed, automation ability, and minimal sample consumption. Only 1 μL of serum is required while the whole immunoaffinity capillary electrophoresis method is performed in less than 50 min. The concomitant use of online immunocapture, transient isotachophoresis, and laserinduced fluorescence detection provides a sensitivity in the low picomolar range and a highly linear fluorescence response over 4 orders of magnitude (IgE concentration ranging from 2.4 to 2400 ng/mL). After validation with a reference material, the method has been successfully applied to the quantification of total IgEs in patient sera. The results compared well with classical ImmunoCap data.