There are significant analytical challenges with the measurement of GH. These include its existence in several structural forms in blood circulation. GH is known to circulate in monomeric or single forms, dimeric or double forms, and oligomeric or multiple forms, A pentameric (5-molecule isoform) can also exist.
Most current commercial immunoassays employ chemiluminescent immunoassay principles with antibodies directed against monomeric forms of GH, which accounts for most of the GH in circulation.
