Human chorionic gonadotropin （hCG） is a peptide hormone produced in pregnancy， that is made by the embryosoon after conception and later by the syncytiotrophoblast（part of the placenta）. Its role is to prevent the disintegration of the corpus luteumof the ovaryand thereby maintain progesterone production that is critical for a pregnancy in humans. hCG may have additional functions， for instance it is thought that it affects the immune tolerance of the pregnancy. Early pregnancy testing generally is based on the detection or measurement of hCG.
Lyophilized hCG although stable at room temperature for 3 weeks， should be stored desiccated below -18℃. Upon reconstitution CG-beta should be stored at 4℃ between 2-7 days and for future use below -18℃. For long term storage it is recommended to add a carrier protein （0.1% HSA or BSA）.
Please prevent freeze-thaw cycles.