Capillary electrophoresis-based immunoassay for insulin antibodies with near-infrared laser induced fluorescence detection

A noncompetitive capillary electrophoresis (CE)-based immunoassay with near-infrared laser induced fluorescence detection (NIR-LIF) for insulin antibodies has been developed. In the assay, insulin was derivatized with a NIR fluorescent dye (NN382; LI-COR). Insulin antibodies were detected via the formation of an immunocomplex. Parameters affecting the separation such as pH, voltage and ionic strength were investigated. Furthermore, it was found that increasing the ramp time of the applied voltage improved the detection limit of the assay by an order of magnitude. The detection limit of the assay was 1.1 nM.