Detection of specific antibodies using immunosubtraction and capillary electrophoresis instrumentation

Solution-phase immunoassays based on capillary electrophoresis (CE) separat ions have been shown to be rapid and simple to perform. The potential for s ample matrix interference and incompatibility with multiplexing conditions for antibody detection when dealing with real samples, however, has prompte d the development of an assay that utilizes an immunosubtraction methodolog y. A model assay for the detection of specific antibodies that relies on so lid-phase extraction, CE and laser-induced fluorescence (LIF) detection is described. The method, called immunocapture-immunosubtraction (ICIS), incor porates an antibody capture/purification protocol using magnetic particles. The detection of specific antibodies is achieved by CE-LIF analysis of a p robe solution following incubation with the captured antibodies. As an exam ple of the ICIS assay's capabilities, the relative quantification of anti-f luorescein in serum is presented.