Cytokeratin 19 Antibody [Unconjugated]

Western blot shows lysates of HT‑29 human colon adenocarcinoma cell line, DU145 human prostate carcinoma cell line, HCT‑116 human colorectal carcinoma cell line, and MCF‑7 human breast cancer cell line. PVDF membrane was probed with 0.1 µg/mL of Sheep Anti-Human Cytokeratin 19 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF3506) followed by HRP-conjugated Anti-Sheep IgG Secondary Antibody (Catalog # HAF016). A specific band was detected for Cytokeratin 19 at approximately 40 kDa (as indicated). This experiment was conducted under reducing conditions and using Immunoblot Buffer Group 1.

Cytokeratin 19 was detected in immersion fixed paraffin-embedded sections of human kidney using Sheep Anti-Human Cytokeratin 19 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF3506) at 3 µg/mL overnight at 4 °C. Tissue was stained using the Anti-Sheep HRP-DAB Cell & Tissue Staining Kit (brown; Catalog # CTS019) and counterstained with hematoxylin (blue). Specific staining was localized to cytoplasm in convoluted tubules. View our protocol for Chromogenic IHC Staining of Paraffin-embedded Tissue Sections.

Simple Western lane view shows lysates of HT‑29 human colon adenocarcinoma cell line, loaded at 0.2 mg/mL. A specific band was detected for Cytokeratin 19 at approximately 50 kDa (as indicated) using 1 µg/mL of Sheep Anti-Human Cytokeratin 19 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF3506) followed by 1:50 dilution of HRP-conjugated Anti-Sheep IgG Secondary Antibody (Catalog # HAF016). This experiment was conducted under reducing conditions and using the12-230 kDa separation system.

MCF-7 human breast cancer cell line was stained with Sheep Anti-Human KRT19 Affinity Purified Polyclonal Antibody (Catalog # AF3506, filled histogram) or control antibody (Catalog # 5-001-A, open histogram) followed by Anti-Sheep IgG PE-conjugated secondary antibody (Catalog # F0126). To facilitate intracellular staining, cells were fixed and permeabilized with FlowX FoxP3 Fixation & Permeabilization Buffer Kit (Catalog # FC012). View our protocol for Staining Membrane-associated Proteins.

Cytokeratin 19 was detected in immersion fixed MCF‑7 human breast cancer cell line using Sheep Anti-Human Cytokeratin 19 Antigen Affinity-purified Polyclonal Antibody (Catalog # AF3506) at 10 µg/mL for 3 hours at room temperature. Cells were stained using the NorthernLights™ 557-conjugated Anti-Sheep IgG Secondary Antibody (red; Catalog # NL010) and counterstained with DAPI (blue). Specific staining was localized to cytoplasm. View our protocol for Fluorescent ICC Staining of Cells on Coverslips.

• Reactivity: Hu
• Applications: WB, Simple Western, IHC, Flow, ICC/IF
• Clonality: Polyclonal
• Host: Sheep
• Conjugate: Unconjugated
• Concentration: LYOPH

Cytokeratin 19 Antibody [Unconjugated] Summary

• Immunogen: E. coli-derived recombinant human Cytokeratin 19
  Thr2-Leu400
  Accession # P08727
• Specificity: Detects human Cytokeratin 19 in direct ELISAs and Western blots. In direct ELISAs, less than 15% cross-reactivity with recombinant human Cytokeratin 14 is observed.
• Source: N/A
• Isotype: IgG
• Clonality: Polyclonal
• Host: Sheep
• Gene: KRT19

Applications/Dilutions

• Dilutions:
  • Western Blot 0.1 ug/mL
  • Simple Western 1 ug/mL
  • Immunohistochemistry 3-15 ug/mL
  • Immunocytochemistry 5-15 ug/mL
  • Intracellular Staining by Flow Cytometry 0.25 ug/10^6 cells

Packaging, Storage & Formulations

• Storage: Use a manual defrost freezer and avoid repeated freeze-thaw cycles.
  • 12 months from date of receipt, -20 to -70 °C as supplied.
  • 1 month, 2 to 8 °C under sterile conditions after reconstitution.
  • 6 months, -20 to -70 °C under sterile conditions after reconstitution.
• Buffer: Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose. *Small pack size (SP) is supplied as a 0.2 µm filtered solution in PBS.
• Preservative: No Preservative
• Concentration: LYOPH
• Reconstitution Instructions: Sterile PBS to a final concentration of 0.2 mg/mL.

Notes

This product is produced by and ships from R&D Systems, Inc., a Bio-Techne brand.

Alternate Names for Cytokeratin 19 Antibody [Unconjugated]

• 40-kDa keratin intermediate filament
• CK19
• CK-19
• Cytokeratin 19
• EndoC
• K19
• K1CS
• keratin 19
• keratin, type I cytoskeletal 19
• keratin, type I, 40-kd
• keratin-19
• Krt19
• MGC15366

Background

Cytokeratin 19 (Keratin, type I cytoskeletal 19; also KRT-19, CK19 and Keratin-19) is a 40-45 kDa, acidic Class I keratin member of the intermediate filament family of proteins. Individual keratins are always expressed in tandem with a second keratin, and these are found in all epithelial cells. The class I KRT-19 heterodimerizes/polymerizes with 50-52 kDa class II KRT-8 (plus KRT-5 and -7) to form 8-10 nm filaments in epidermal stem cells, secretory gland (sweat; mammary; bile duct) simple epithelium, and neuroendocrine epidermal Merkel cells. It may represent a viable marker for skin stem cells. In skin, Cytokeratin 19 forms filaments in the fetal epithelium, and then progressively decreases with age, being virtually absent by age 17. Human Cytokeratin 19 is 400 amino acids (aa) in length. It contains an N-terminal "head" region (aa 1-79) and a subsequent "rod" region (aa 80-387), but is absent a typical C-terminal tail region. Cytokeratin 19 possesses at least 5 utilized phosphorylation sites plus one acetylated Lys residue. Based on other keratins, and the presence of an Asp at position 238, there may be caspase cleavage-generated isoforms. Full length human Cytokeratin 19 (aa 2-400) shares 82% aa sequence identity with mouse Cytokeratin 19.

Limitations

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Primary Antibodies are guaranteed for 1 year from date of receipt.

Bioinformatics

• Gene Symbol: KRT19
• Uniprot:
  • P08727()