Technical Data
Claudin 18 (CLDN18)
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.1 The lung-specific form is a downstream target gene regulated by the T/EBP/NKX2.1 transcription factor.1 A splice variant lacking the C-terminal cytoplasmic domain also exists in mouse, but has not been confirmed in human.1 Human claudin-18 demonstrates 88% amino acid sequence identity to the mouse protein.1 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.1 These features suggest a potentially important role for claudin-18 in the structure and function of tight junctions in the lung and
stomach.1 Claudin-18 expression has also been reported in the inner ear.2

Suitable for use in Western Blot, Immunofluorescence, and Immunohistochemistry Other applications not tested.

Recommended Dilution:
Western Blot: 1-3ug/ml
Immunohistochemistry (frozen): 5ug/ml
Immunofluorescence: 5ug/ml
Optimal dilutions to be determined by the researcher.

Positive Control: Mouse lung and stomach homogenates

Storage and Stability:
May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for at least 12 months. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
PabIgGAffinity Purified
100ug-20CBlue IceMouseRabbit
~0.25 mg/ml
Synthetic peptide derived from the C-terminal region of the human Claudin-18 protein, which differs from mouse by 4 conservative amino acid replacements and one non-conservative amino acid replacement
Purified by immunoaffinity chromatography
Supplied as a liquid in PBS, pH 7.2, 0.09% sodium azide.
Recognizes mouse Claudin-18 protein at ~29 kD. Species sequence homology: Human
Intended for research use only. Not for use in human, therapeutic, or diagnostic applications.
1. Niimi T, et al. Mol Cell Biol 21:7380-7390, 2001. 2. Kitajiri SI, et al. Hear Res 187:25-34, 2004.