Zeta Cytokeratin 19 Antibody. Zeta’s rabbit recombinant antibody recognizes Cytokeratin 19 (CK19), specifically to the rod domain of human cytokeratin 19 (CK19), a polypeptide of 40kDa. Cytokeratin 19 (CK19) is expressed by the sweat gland, mammary gland ductal and secretory cells, bile ducts, gastrointestinal tract, bladder urothelium, oral epithelia, esophagus, and ectocervical epithelium. Using immunohistochemistry, the antibody to Cytokeratin 19 (CK19) identifies a wide variety of epithelial malignancies, including colon, stomach, pancreas, biliary tract, liver, and breast adenocarcinomas. Additionally, Zeta’s antibody to Cytokeratin 19 (CK19) can be used to identify thyroid carcinoma of the papillary type, although 50%-60% of follicular carcinomas are also labeled. Zeta’s antibody to Cytokeratin 19 (CK19) is a useful marker for detecting tumor cells in lymph nodes, peripheral blood, bone marrow, and breast cancer.