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Assay Type
Solid Phase Sandwich ELISA
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Format
96-well strip plate
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Assay Length
3.5 hours
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Sample Type & Volume Required Per Well
Cell Culture Supernates (50 uL), Serum (50 uL), EDTA Plasma (50 uL), Heparin Plasma (50 uL), Citrate Plasma (50 uL)
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Sensitivity
7.5 pg/mL
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Assay Range
31.2 - 2,000 pg/mL (Cell Culture Supernates, Serum, EDTA Plasma, Heparin Plasma, Citrate Plasma)
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Specificity
Natural and recombinant human IL-8
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Cross-reactivity
< 0.5% cross-reactivity observed with available related molecules.< 50% cross-species reactivity observed with species tested.
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Interference
No significant interference observed with available related molecules.
Control Available
QC23, Quantikine Immunoassay Control Group 8 -
Product Summary
The Quantikine Human IL-8 Immunoassay is a 3.5 hour solid phase ELISA designed to measure human IL-8 in cell culture supernates, serum, and plasma. It is based on antibodies raised against the 72 aa variant of human IL-8 derived from E. coli. It is calibrated with the same recombinant factor. This immunoassay accurately quantitates recombinant human IL-8. Measurement of natural human IL-8 or the 77 aa variant of human IL-8 gave results parallel to the standard curves obtained using the E. coli-expressed Quantikine kit standards. These results indicate that this kit can be used to determine relative mass values for natural human IL-8.
Precision
Intra-Assay Precision (Precision within an assay) Three samples of known concentration were tested on one plate to assess intra-assay precision.
Inter-Assay Precision (Precision between assays) hree samples of known concentration were tested in separate assays to assess inter-assay precision.
Serum, EDTA Plasma, Heparin Plasma, Citrate Plasma | Intra-Assay Precision | Inter-Assay Precision |
Sample | 1 | 2 | 3 | 1 | 2 | 3 |
n | 20 | 20 | 20 | 20 | 20 | 20 |
Mean | 168 | 526 | 1093 | 196 | 581 | 1160 |
Standard Deviation | 9.4 | 28.6 | 70.7 | 14.5 | 56.6 | 70.2 |
CV% | 5.6 | 5.4 | 6.5 | 7.4 | 9.7 | 6.1 |
Cell Culture Supernates | Intra-Assay Precision | Inter-Assay Precision |
Sample | 1 | 2 | 3 | 1 | 2 | 3 |
n | 20 | 20 | 20 | 20 | 20 | 20 |
Mean | 115 | 386 | 802 | 132 | 410 | 817 |
Standard Deviation | 5.3 | 17 | 37.9 | 10.7 | 28 | 42.4 |
CV% | 4.6 | 4.4 | 4.7 | 8.1 | 6.8 | 5.2 |
Recovery
The recovery of IL-8 spiked to three different levels throughout the range of the assay in various matrices was evaluated.
Sample Type | Average % Recovery | Range % |
Cell Culture Media (n=5) | 98 | 85-114 |
Citrate Plasma (n=5) | 105 | 95-114 |
EDTA Plasma (n=5) | 103 | 97-111 |
Heparin Plasma (n=5) | 102 | 92-107 |
Serum (n=5) | 98 | 88-106 |
Linearity
To assess the linearity of the assay, samples were spiked with high concentrations of IL-8 in various matrices and diluted with the appropriate Calibrator Diluent to produce samples with values within the dynamic range of the assay.
Preparation and Storage
Background: IL-8/CXCL8
Interleukin-8 (IL-8), also known as CXCL8, is a chemokine that is upregulated at sites of inflammation where it promotes neutrophil infiltration and activation. IL-8 can form homodimers and heterodimers with CXCL4/PF4. Its bioactivity is regulated by proteolytic truncations, citrullination, and the decoy receptor DARC. IL-8 signals through CXCR1/IL-8 RA, which is also used by CXCL6, and through CXCR2/IL-8 RB, which is used by multiple CXC chemokines. IL-8 also binds to Serpin A1/alpha-1 Antitrypsin which prevents IL-8 interaction with CXCR1.