Human Chorionic Gonadotropin (HCG) is a glycoprotein, which is secreted in large quantities by normal trophoblasts. It is present only in trace amounts in non-pregnant urine and sera but rises sharply during pregnancy. HCG is composed of two non-identical, non-covalently linked polypeptide chains designated as the a-and b-subunits. The a-subunit of HCG is nearly identical to that of thyroid stimulating hormone (TSH), follicle stimulating hormone (FSH), and luteinizing hormone (LH). A germ cell tumor which is positive for cytokeratin, placental alkaline phosphatase (PLAP), and HCG but negative for EMA and AFP is probably a choriocarcinoma. Applications: Suitable for use in FLISA. Other applications not tested. Recommended Dilution: Optimal dilutions to be determined by the researcher. Storage and Stability: Store product at 4C if to be used immediately within two weeks. For long-term storage, aliquot to avoid repeated freezing and thawing and store at -20C. Aliquots are stable at -20C for 12 months after receipt. Dilute required amount only prior to immediate use. Further dilutions can be made in assay buffer. Caution: FITC conjugates are sensitive to light. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Note: Applications are based on unconjugated antibody.