ABSTRACT
The range of analyte concentrations encountered in medical diagnostics and clinical chemistry is extremely large. This range has an upper limit greater than 10−3 M for analytes such as glucose and cholesterol and a lower limit less than 10−9 M for drugs and hormones. It is for the detection of these low-level analytes that the application of immunological techniques, and in particular immunoassays, is essential [1]. Immunoassay is an analytical method based on antigenantibody interaction. Antibodies are protein molecules (produced by living animals) that recognize (bind to) certain very specific antigens at a molecular level. The ability of antibodies to form complexes with specific antigen molecules is the basis of immunoassays. Immunoassay is a specific and sensitive technique
due to the high selectivity of antigen recognition and the high affinity of immunointeraction. Contemporary immunological techniques allow production of antibodies against a great number of antigens, and they enable immunoanalysis of many substances [2]. Immunoassays are now well established as an essential analytical technique in medical diagnostics, facilitating the measurement of an increasing number of analytes of clinical significance, and are now routinely used for the detection of small molecules such as drugs, through peptides, to large macromolecules such as proteins, including antibodies, and whole cells [3].
