Product Usage Information
Western Blotting: 1:1000
Immunohistochemistry (Paraffin): 1:50
Immunofluorescence (Immunocytochemistry): 1:50
Flow Cytometry (Fixed/Permeabilized): 1:100
Storage
Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA, 50% glycerol and less than 0.02% sodium azide. Store at -20°C. Do not aliquot the antibody. For a carrier free (BSA and azide free) version of this product see product # 51274 .
Protocol
Available protocols: Western Blotting, Immunohistochemistry (Paraffin), Immunofluorescence (Immunocytochemistry), Flow Cytometry (Fixed/Permeabilized)
Specificity / Sensitivity
Keratin 8/18 (C51) Mouse Monoclonal Antibody detects endogenous levels of total keratins 8 and 18. This antibody does not cross-react with other keratins.
Species Reactivity: Human, Monkey
Source / Purification
Monoclonal antibody (isotype: IgG1) is produced by immunizing a BALB/c mouse with a cytoskeleton preparation from HeLa cells.
Background
Keratins (cytokeratins) are intermediate filament proteins that are mainly expressed in epithelial cells. Keratin heterodimers composed of an acidic keratin (or type I keratin, keratins K9-K28) and a basic keratin (or type II keratin, keratins K1-K8 and K71-K80) assemble to form filaments. Keratin isoforms demonstrate tissue- and differentiation-specific profiles that make them useful as research and clinical biomarkers (1,2). Dysregulation/mutations in keratin genes can lead to a variety of disorders affecting the skin, hair, nails, and other epithelial tissues (3). While expression of keratins can be variable, immunohistochemical staining of keratins is widely used to help in the identification and classification of epithelial tumors, and may also provide prognostic information. Keratins 8 and 18 (K8/K18) are expressed in simple epithelia of normal tissue, as well as in adenocarcinomas of the breast, lung, ovary, and gastrointestinal tract. Keratin 17 is expressed in basal keratinocytes of stratified epithelia, hair follicles, and sebaceous glands. Onset of keratin 17 expression coincides with the definition of major epithelial lineages during skin development (4). Keratin 14 (K14) is expressed in basal cells of stratified epithelia, and in basal-like subtypes of breast cancer and squamous cell carcinomas. Keratin 19 (K19) is expressed in glandular epithelia, including the liver, gallbladder, and pancreas, as well as in adenocarcinomas of the breast, thyroid, and bile duct. Keratin 20 (K20) is expressed in gastrointestinal epithelium, urothelium, and Merkel cells in the skin, as well as in colorectal carcinomas and some urothelial carcinomas. Keratin 5/6 (K5/6) is expressed in basal cells of stratified epithelia, including the skin, prostate, and breast, as well as in basal-like breast cancers, squamous cell carcinomas, and some lung carcinomas. Keratin 7 (K7) is expressed in glandular epithelia, such as those in the lung, breast, and female reproductive tract, as well as in adenocarcinomas of the lung, breast, and ovary (5,6). Keratins, particularly K8, K18, and K19, serve as biomarkers for identification of circulating tumor cells (CTCs) (5). Post-translational modifications, including phosphorylation, acetylation, ubiquitylation, sumoylation, glycosylation, and transamidation, have been shown to affect the functions of keratins in normal and disease states (6). Understanding the molecular mechanisms underlying these PTMs may provide insights into cancer pathogenesis.
Alternate Names
CARD2; Cell proliferation-inducing gene 46 protein; cell proliferation-inducing protein 46; CK-18; CK-8; CK8; CYK18; CYK8; cytokeratin 18; cytokeratin 8; Cytokeratin-18; Cytokeratin-8; K18; K1C18; K2C8; K8; keratin 18; keratin 18, type I; keratin 8; keratin 8, type II; Keratin-18; Keratin-8; Keratin, type I cytoskeletal 18; Keratin, type II cytoskeletal 8; KO; KRT18; KRT8; Type-II keratin Kb8
