The Cancer Antigen 125 (CA-125) CLIA Kit is designed, developed, and produced for the quantitative measurement of human CA125 level in serum samples. The assay utilizes a two-site “sandwich” technique with two antibodies that bind to different epitopes of CA125. Assay calibrators, controls, or patient serum samples are added directly to a reaction vessel together with magnetic particles antibody. The magnetic particles capture the CA125in the form of “magnetic particles–CA-125 antibody–CA125–acridinium ester CA-125 antibody”. Materials bound to the solid beads are held in a magnetic field while unbound materials are washed away. Then trigger solutions are added to the reaction vessel, and light emission is measured with the ECL100 or ECL 25 analyzer. The relative light units (RLU) are proportional to the concentration of a CA-125 in the sample. The amount of analyte in the sample is determined from a stored, multi-point calibration curve and reported in serum CA125 concentration.