Hepatitis B Surface Antigen, Pre-S2 (1-32) (Pre-S (120-151)) (HBsAg)

Hepatitis B is an infection of the liver caused by the hepatitis B virus. Approximately 5-10% of adults and 90% of babies who are infected with HBV will go on to carry the virus for the rest of their lives. These people will pass the virus onto others. HBV is excreted in body fluids such as semen, saliva, blood and urine in persons with acute or chronic infection. The route of transmission can include homosexual or heterosexual activity, blood-borne exposure (needles, transfusion), mother-infant, close personal contact and even by consuming contaminated food or water. Thus, Hepatitis B has become a major public health concern. When HBV invades the body it causes liver damage through induction of auto-immunity. Liver cell injury results from cytotoxic T cell activity rather than viral cytotoxic activity. The principal screening test for detecting current (acute or chronic) HBV infection is the identification of HBsAg, an envelope lipoprotein. This is the first immunological marker to appear in a patient's serum and exist in high quantities in the blood. Patients who are HBsAg positive develop chronic persistent hepatitis (CPH) and chronic active hepatitis (CAH). Patients with CPH usually remain in good health. Those with CAH have progressive liver damage with the outcome being portal fibrosis, cirrhosis, or hepatocellular carcinoma. Screening for HBsAg is recommended for all donors, pregnant women and those individuals who at high risk. Presence of this marker is conclusive proof of HBV infection. This immunoassay measures HBsAg through antigen-antibody interactions. Sequence (linear): Met-Gln-Trp-Asn-Ser-Thr-Ala-Phe-His-Gln-Thr-Leu-Gln-Asp-Pro-Arg-Val-Arg-Gly-Leu-Tyr-Leu-Pro-Ala-Gly-Gly-Ser-Ser-Ser-Gly-Thr-Val , Storage and Stability: , Lyophilized powder may be stored at 4°C for short-term only. Stable for 12 months at -20°C. Reconstitute to nominal volume (see reconstitution instructions for peptides) and store at -20°C. For maximum recovery of product, centrifuge the original vial prior to removing the cap. Further dilutions can be made in assay buffer. ,