Enzyme ImmunoAssay (EIA) is a technique to detect and quantify antigens (proteins, hormones…) or antibodies in samples. It relies on the ability of an antibody to bind a specific antigen. Either the antibody or the antigen is labelled with an enzyme whose substrate is a chromogen or a fluorogen converted in a measurable product (color or fluorescence).|Enzyme-linked Immunosorbent Assay (ELISA) is a type of EIA using a solid phase (ex: microtiter plate) coated with an antigen immobilizing the molecule to detect. Over the time, scientists have extended the term ELISA to EIAs using an antibody coating the solid phase. That explains why our EIA kits using coated antibodies are also called ELISA kits.|Prolactin (PRL) is a pituitary hormone whose molecular weight is approximately 23000 Daltons. It is a single polypeptide chain composed of about 200 amino acid residues with three disulphide bonds. In mammals prolactin has been claimed to exert a wide range of different physiological effects. These include stimulation of mammary gland development and lactation, hair maturation, synergism with androgen in male sex accessory growth and maintenance and secretion of corpus luteum. PRL is predominantly under inhibitory control by the hypothalamus. Stimulation of prolactin release can be mediated by dopamine and thyrotrophin-releasing hormone(TRH).