CCD-camera based capillary chemiluminescent detection of retinol binding protein Original Research Article

A chemiluminescence (CL) assay for retinol-binding protein (RBP) was designed and optimized using a charge coupled device (CCD)-camera based detection system. A sandwich ELISA was designed based on the anti-RBP antibodies immobilized in glass capillaries pre-treated with silica sol. The immobilization was predominantly by physisorption of the protein on the silica surface. The RBP bound to the anti-RBP antibodies was detected by using an anti-RBP-horseradish peroxidase (HRP) conjugate. The reaction of the HRP with hydrogen peroxide and luminol and 4-iodophenol generated the CL. The CL emitted from the glass capillaries was detected by a cooled slow scan CCD camera at an optimized exposure time. The approximately linear range of RBP determination was between 11 pg ml−1 and 11 ng ml−1 with a coefficient of variation of 5–11% (n=6) over this range.