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.|Calcitonin Gene Related Peptide (CGRP) is a potent vasodilator, and also elicits a number of other biological effects. Average plasma levels of CGRP have been reported to be from 0.8 pmol/L to 71 pmol/l (3 pg/mL to 269 pg/mL) in normal subjects. Increases in circulating CGRP levels have been noticed during hemodialysis, pregnancy, exacerbation of asthma, and in cases of medullary thyroid carcinoma.