Enzyme immmunoassay (ELISA) for the determination of human IgM antibodies in serum or plasma directed against Chlamydia trachomatis. For research use only, not for use in diagnostic procedures.The reaction isbased on the specific interaction of antibodies with their corresponding antigen. The teststrips of the microtiter plate are coated with specific antigens of the pathogen of interest. Ifantibodies in the serum sample are present, they bind to the fixed antigen. A secondaryantibody, which has been conjugated with the enzyme alkaline phosphatase, detects andbinds to the immune complex. The colourless substrate p-nitrophenylphosphate is thenconverted into the coloured product p-nitrophenol. The signal intensity of this reactionproduct is proportional to the concentration of the analyte in the sample and is measuredphotometrically.