Immunohistochemistry analysis of Claudin-18 (Mid) showing staining in the membrane and cytoplasm of paraffin-embedded mouse stomach tissue (right) compared to a negative control without primary antibody (left). To expose target proteins, antigen retrieval was performed using 10mM sodium citrate (pH 6.0), microwaved for 8-15 min. Following antigen retrieval, tissues were blocked in 3% H2O2-methanol for 15 min at room temperature, washed with ddH2O and PBS, and then probed with a Claudin-18 (Mid) Rabbit Polyclonal Antibody (388100) diluted in 3% BSA-PBS at a dilution of 1:100 overnight at 4°C in a humidified chamber. Tissues were washed extensively in PBST and detection was performed using an HRP-conjugated secondary antibody followed by colorimetric detection using a DAB kit. Tissues were counterstained with hematoxylin and dehydrated with ethanol and xylene to prep for mounting.
|Tested species reactivity||Human, Mouse|
|Published species reactivity||Rat, Human|
|Host / Isotype||Rabbit / IgG|
|Immunogen||Synthetic peptide derived from an internal region of the human Claudin-18 protein, which differs from mouse by one conservative amino acid replacement.|
|Purification||Antigen affinity chromatography|
|Storage buffer||PBS, pH 7.4|
|Contains||0.1% sodium azide|
|Tested Applications||Dilution *|
|Immunofluorescence (IF)||Assay Dependent|
|Immunohistochemistry (Frozen) (IHC (F))||Assay Dependent|
|Immunohistochemistry (Paraffin) (IHC (P))||1:20-1:200|
|Western Blot (WB)||Assay Dependent|
* Suggested working dilutions are given as a guide only. It is recommended that the user titrate the product for use in their own experiment using appropriate negative and positive controls.
Claudin-18 is a tight junction protein expressed as lung-and stomach-specific isoforms which are generated by alternative splicing of the claudin-18 gene. The lung-specific form is a downstream target gene regulated by the T/EBP/NKX2.1 transcription factor. A splice variant lacking the C-terminal cytoplasmic domain also exists in mouse, but has not been confirmed in human. Human claudin-18 demonstrates 88% amino acid sequence identity to the mouse protein. Immunohistochemical studies have demonstrated complete membrane localization of claudin-18 in lung and stomach epithelial cells, while electron microscopy has shown that it is concentrated in the cell-cell borders of these cells. These features suggest a potentially important role for claudin-18 in the structure and function of tight junctions in the lung and stomach. Claudin-18 expression has also been reported in the inner ear. Because of its highly restricted expression pattern in normal tissues and frequent activation in numerous human cancers, claudin-18 may represent an important target for antibody therapy.
For Research Use Only. Not for use in diagnostic procedures. Not for resale without express authorization.
|Rat||Not Cited||Hypoxia increases transepithelial electrical conductance and reduces occludin at the plasma membrane in alveolar epithelial cells via PKC-¿ and PP2A pathway.||Caraballo JC,Yshii C,Butti ML,Westphal W,Borcherding JA,Allamargot C,Comellas AP||American journal of physiology. Lung cellular and molecular physiology (300:L569)||2011|
|Human||Not Cited||Allogeneic human mesenchymal stem cells restore epithelial protein permeability in cultured human alveolar type II cells by secretion of angiopoietin-1.||Fang X,Neyrinck AP,Matthay MA,Lee JW||The Journal of biological chemistry (285:26211)||2010|
|Human||Not Cited||Claudin-18 splice variant 2 is a pan-cancer target suitable for therapeutic antibody development.||Sahin U,Koslowski M,Dhaene K,Usener D,Brandenburg G,Seitz G,Huber C,Türeci O||Clinical cancer research : an official journal of the American Association for Cancer Research (14:7624)||2008|