Immunoassay for glial fibrillary acidic protein: Antigen recognition is affected by its phosphorylation state

Glial fibrillary acid protein (GFAP) is used commonly as a marker of astrogliosis and astrocyte activation in several situations involving brain injury. Its content may be measured by immunocytochemistry, immunoblotting or enzyme-linked immunosorbent assay (ELISA), usually employing commercial antibodies. Two major post-translational modifications in GFAP (phosphorylation and proteolysis) may alter the interpretation of results or for …