Reagent, Beta LH is a hormone synthesized and secreted by gonadotropes in the anterior lobe of the pituitary gland. LH has a beta subunit of 121 amino acids (LHB) that confers its specific biologic action and is responsible for interaction with the LH receptor. This beta subunit contains the same amino acids in sequence as the beta sub unit of hCG and both stimulate the same receptor, however the hCG beta subunit contains an additional 24 amino acids, and both hormones differ in the composition of their sugar moieties.