Chromatographic approaches to immunoassays

A number of recent research articles have examined the combined use of high-performance liquid chromatography (HPLC) and immunoassays. The new method, known as a chromatographic immunoassay or high-performance immunoaffinity chromatography (HPIAC), offers several advantages over traditional solid-phase immunoassays, including improved speed, precision and ease of coupling to other methods. This review will examine some applications of chromatographic immunoassays in the fields of clinical and pharmaceutical chemistry. Examples will include the use of HPLC systems and immobilized antibody columns for performing direct analyte detection, competitive binding immunoassays, immunometric assays and on-line immunoextraction prior to quantitation by other analytical methods. The general principles behind each of these approaches are discussed along with the relative advantages and disadvantages of each assay format.