Human CA199

This unconjugated liquid preparation of recombinant Human CA199 from Antibodies.com provides 10 µg of purified antigen for use as a reference standard or immunogen in cancer biomarker research. CA19-9 (sialyl Lewis A) is a glycoprotein tumor-associated antigen expressed on pancreatic ductal epithelium and elevated in sera of patients with pancreatic, colorectal, and gastric adenocarcinomas; a healthy serum reference threshold is commonly cited as below 37 U/mL. The unconjugated format gives researchers flexibility to conjugate the protein to enzymes, biotin, or fluorophores for tailored ELISA, immunohistochemistry, or western blot workflows, or to use it directly as a coating antigen. Shipped in liquid form, the product is supplied in a vial; for long-term stability, aliquot and store at -20 °C or below, avoid repeated freeze-thaw cycles, and protect from light to preserve activity. Research use only.