IL-8 (CXCL8) ELISA Kits

Interleukin-8 (IL-8) — also known as CXCL8 — is a chemokine produced by fibroblasts, monocytes, and vascular endothelial cells in response to stimuli such as inflammatory cytokines. IL-8 exists as two isoforms of 72 or 77 amino acids, both of which are CXC chemokines that bind to the CXCR1 and CXCR2 receptors to initiate intracellular signaling.
IL-8 is well known as a neutrophil chemoattractant; it induces chemotaxis of target cells to sites of infection and further promotes phagocytosis, thereby acting as a critical mediator of inflammation in the body. Its roles in inflammatory responses include, for example, the mobilization of neutrophils from bone marrow to peripheral blood, neutrophil activation, and enhanced adhesion of neutrophils to vascular endothelial cells¹⁾. In addition to neutrophils, target cells of IL-8 include T lymphocytes, basophils, activated eosinophils, and vascular endothelial cells²⁾. IL-8 has been studied in relation to a wide range of diseases and is of particular interest in fields such as rheumatoid arthritis, respiratory diseases including asthma, arteriosclerosis, gout, periodontitis, and cancer.

The LBIS™ Human IL-8 ELISA Kit is a sandwich ELISA kit designed for the quantitative measurement of human IL-8 (CXCL8). This kit enables highly sensitive quantification of IL-8 (CXCL8) in biological samples. The standard included in the kit is a recombinant protein produced in Escherichia coli.

Kit Performance

Assay target	IL-8 (CXCL8)
Calibration curve range	0.686 - 500 pg/mL
Analysis sample	Human Serum/Plasma (EDTA・Heparin) /Cell culture supernatant*
Sample volume	50 μL (2x dilution)
Measurement duration	Approx. 3 hours and 50 minutes
Wavelength	Primary wavelength : 450 nm Reference wavelength : 620 nm

• Measurement availability depends on the culture medium.
  When using cell culture supernatant as a sample, please make sure to perform recovery test and dilution linearity test on the culture medium before use.

Example of Calibration Curve

Measurement of IL-8 (CXCL8) in Human Serum and Plasma

[Result]
IL-8 was detected even in samples which were below the lower limit of quantification of another commercially available product.

1. Tsuji, H. and Matsushima, K.: Journal of Atherosclerosis and Thrombosis, 24(1-2), 15(1996). (Japanese)
   Properties of Interleukin-8 (IL-8) and MCAF (monocyte chemotactic and activating factor)/MCP-1 (monocyte chemoattractant protein-1) and those receptors
2. Fujishima, S.: Japanese Journal of Inflammation, 18(6), 433(1998). (Japanese)
   A prominent role of IL-8 in various inflammatory lung diseases and multiple organ dysfunction syndrome