ABSTRACT
Immunoassays make use of the excellent binding specificity of antibodies and have been used for protein detection since the 1960s (Yalow and Berson, 1960). Antibodies can be directed with high specificity to a large variety of antigens. The still most popular and used technique for protein quantification, ELISA, was developed in the 1960s (Engvall and Perlman, 1971). Sandwich ELISA uses one antibody to capture the analyte and an enzyme immobilized by a second antibody for detection. The enzyme catalyzes a colorimetric reaction which product is readily detected for quantification. Through the reaction the signal from the analyte increases linearly in time and low concentrations of the antigen can be detected.
