The most effective use of immunoassay methods is to make rapid screening decisions before samples are analyzed by slower and more expensive methods. The CAPE Technologies High Performance Dioxin/Furan Immunoassay Kit is designed to screen samples at selected PCDD/F levels. In a properly designed screening program, this Enzyme Immunoassay (EIA) supplements conventional methods, but does not replace them.

In summary, all samples from a project are screened using the immunoassay method. All samples which are positive at the decision level are then analyzed by the standard method. Some randomly selected fraction (typically 5 to 20%) of negative samples are also analyzed by the standard method. Thus, most EIA negative samples are never analyzed by the conventional method.

Project cost models provided by CAPE Technologies are based on this approach. This approach has been embodied in the successful US EPA 4000 series of immunoassay screening methods (PCB, PAH, etc.). A more complete description of this screening approach and its application to dioxin analysis is being developed.