Claudin-5 ELISA Kit (CLDN5)

Full Name: Claudin-5 ELISA Kit (CLDN5)
Reactivity: Human
Sample Type: Tissue Homogenates, Biological Fluids, Plasma, Serum
Sensitivity: 0.094 ng/ml


Claudin-5 consists of 4 transmembrane domains, a short NH2 terminus, two extracellular loops (ECL), a short intracellular loop and a longer COOH terminus. It is localised specifically to the endothelial cell layer in the brain, lung, liver, kidney and skin while it is expressed in the epithelial cell layer in the stomach, colon, ovary and testis. It is highly expressed on the luminal surface of the small intestine, but is not detected in the mucosal epithelium of any other organ. It is also highly expressed on both sides of the brain blood barrier. It has been proposed that it functions as a tight junction protein in this area. When exposed to the inflammation indicators bile salt and lipopolysaccharide (LPS) during Caesarean section surgery, CLDN5 expression has been seen to be increased. In addition to enterocytes in the apical membrane, its expression is elevated in the gut lumen and intestine’s epithelial cells.

Claudin-5 regulates the paracellular permeability in the blood-brain barrier and is the enriched tight junction protein at the BBB. The vascular permeability to small molecules was markedly increased in the CLDN knockout mouse brain. It is implicated in neurodegenerative disorders such as; Alzheimer’s disease, neuroinflammatory disorders (multiple sclerosis) and psychiatric disorders (depression and schizophrenia).


Human claudin-5 ELISA kit can measure concentrations of CLDN5 (claudin-5, BEC1, CPETRL1, TMVCF1) present is human biological fluids, serum, plasma and tissue homogenate samples.


All reagents supplied need to be stored at 2 °C – 8 °C, unopened reagents will retain reactivity until expiration date. Do not use reagents beyond this date.

  • One 96-Well Plate: Pre-coated with anti-CLDN5 antibody.
  • Standards: Lyophilized recombinant.
  • Sample/Standard Dilution Buffer.
  • Biotinylated-labelled Antibody.
  • Antibody Dilution Buffer.
  • HRP-Streptavidin Conjugate (SABC).
  • SABC Dilution Buffer.
  • TMB Substrate.
  • Wash Buffer (25x).
  • Plate Sealer.
  • Product Instructions.


For this claudin-5 ELISA kit it is recommended that a standard curve is generated for each assay carried out.

Standard Curve: 0, 0,156, 0.312, 0.625, 1.25, 2.5, 5, 10 ng/ml.
Reactivity: Human
Sensitivity: 0.094 ng/ml
Range: 0.156 – 10 ng/ml
Principle: Sandwich
Application: Research Use Only.


– Specificity: Highly specific for CLDN5, no cross reactivity or interference between CLDN5 and analogues was detected.
– Recovery: Serum (93 – 100%), EDTA Plasma (92 – 100%), Heparin Plasma (86 – 99%).
– Linearity: Serum (98 – 104%), EDTA Plasma (84 – 100%), Heparin Plasma (80 – 95%).
– Precison Intra-Assay: CV < 8%.
– Precison Inter-Assay: CV < 10%.
– Stability: Less than 10%.


  1. Claudin-5: gatekeeper of neurological function. Fluids Barriers CNS. (2019) 16 (1): 3. Greene C., et al.
  2. Modifying the blood-brain barrier by targeting claudin-5: Safety and risks. Ann N Y Acad Sci. (2022) 1514 (1): 62-69. Wakayama E., et al.
  3. Social stress induces neurovascular pathology promoting depression. Nat Neurosci. (2017) 20 (12): 1752-1760. Menard C., et al.
  4. Hyperglycemia and advanced glycation end products disrupt BBB and promote occludin and claudin-5 protein secretion on extracellular microvesicles. Sci Rep. (2020) 10 (1): 7274. Rom S., et al.


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