Automated immunoassay analyzers from several different manufacturers are in commercial use and still others are in development. The technical demands of these assay markets requires detection technologies which are highly sensitive, not overly prone to interferences, robust and simple to use. Chemiluminescent processes have sufficient sensitivity and so are well suited for these applications.
Most assays are heterogeneous and require separation of bound from unbound label.
These assays are simpler to develop but somewhat more complicated to perform. A homogeneous assay, in contrast, requires the light-producing reaction to be affected in some way by binding of the ligand to its receptor. One reason accounting for the growing popularity of chemiluminescent assays is their exquisite detection sensitivity. The most serious source of background signal comes from the label being nonspecifically associated with the analyte through nonspecific binding events. This problem occurs in all detection systems.