Merck, CG5-1VL, Chorionic gonadotropin human

General description
Glycoprotein hormone consisting of a 92-amino acid α-chain which is identical to that of LH, FSH, and TSH; and a distinct 149-amino acid β-chain. Produced by chorionic tissue and responsible for maintaining the corpus luteum during early pregnancy. Also produced by trophoblast cell neoplasms, which are marked by elevated free hCG β-chains and hyperglycosylated hCG.
Chorionic gonadotropin human (CGA or hCG) is a heterodimer and belongs to the cystine knot growth factor superfamily. It exists as six variants namely hCGn, hCGβ, hCGβn, hCGβcf and hCGα including hCG. CGA is mapped to human chromosome 6q14.3. hCG comprises of α and β chain.
Application
Chorionic gonadotropin human has been used:
to induce oocyte maturation in cultured follicles
along with pregnant mare serum gonadotropin (PMSG) to induce superovulation in mice
as medium component for fetal testes culture to aid steroidogenic responsiveness

Biochem/physiol Actions
Elevated levels of hCG is observed in trophoblastic cancer. hCG levels are indicators of pregnancy and β subunit is majorly present in urine samples. hCG isoform detection is useful in the diagnosis and management of trophoblastic related diseases including carcinomas.
Preparation Note
When reconstituted with water to a concentration of 1,000 IU/mL, the vial will also contain 0.02 M sodium phosphate buffer (pH approx. 7.2) and 20 mg/mL of mannitol.
Analysis Note
The calculated value is based on the USP method for human Chorionic Gonadotrophin, to meet 5,000 IU per vial, with a tolerance of not less than 80.0% and not more than 125.0% of the potency stated.