Sex Hormone Binding Globulin ELISA (SHBG ELISA)

The principle of the following enzyme immunoassay follows a typical two-step capture or “sandwich” type assay. The assay makes use of two highly specific monoclonal antibodies: a monoclonal antibody specific for SHBG is immobilized onto the microwell plate and another monoclonal antibody specific for a different region of SHBG is conjugated to horseradish peroxidase (HRP). SHBG from the sample and standards are allowed to bind to the plate, which is then washed, and subsequently incubated with the HRP conjugate. After a second washing step, the enzyme substrate is added. The enzymatic reaction is terminated by the addition of the stop solution. The absorbance is measured on a microtiter plate reader. The intensity of the color formed by the enzymatic reaction is directly proportional to the concentration of SHBG in the sample. A set of standards is used to plot a standard curve from which the amount of SHBG in samples and controls can be directly read.