Product Overview
The BioDeviceLab Human IL-18 ELISA Kit is a high-performance enzyme-linked immunosorbent assay developed for the quantitative determination of IL-18, a key pro-inflammatory cytokine produced by epithelial cells, macrophages, dendritic cells, and monocytes following inflammasome activation. IL-18 is synthesized as an inactive precursor and becomes biologically active after cleavage by caspase-1, linking it tightly to innate immune sensing and microbial-triggered inflammatory pathways.
In gastrointestinal systems, IL-18 is a critical biomarker of epithelial stress responses, microbial sensing, inflammasome signaling, and mucosal immune activation. IL-18 contributes to downstream immune programs including IFN-γ induction and Th1/Th17 polarization and is implicated in inflammatory bowel disease, infection-driven inflammation, and barrier dysfunction. In gut-on-chip platforms, IL-18 serves as a robust readout of inflammasome activation, epithelial–immune signaling, and therapeutic modulation of innate immune pathways. This assay combines high analytical sensitivity, strong specificity, and reproducible performance, making it suitable for mechanistic studies and biodevice validation workflows.
Intended Use
This kit is intended for the quantitative determination of IL-18 in:
• Serum
• Plasma
• Cell culture supernatants
Applications include gut-on-chip innate immune activation studies, inflammasome signaling analysis, host–microbiome interaction research, infection and epithelial injury models, drug and biologic screening, and biodevice calibration and benchmarking.
Assay Principle
This assay employs a sandwich ELISA format:
• IL-18 present in the sample binds to capture antibodies immobilized on a 96-well microplate.
• A biotinylated detection antibody specific to IL-18 binds to the captured cytokine.
• An enzyme conjugate is added, followed by chromogenic substrate (TMB).
• The enzymatic reaction generates a colorimetric signal measured at 450 nm.
• Absorbance is directly proportional to the IL-18 concentration in the sample.
Calibration Curve
• A calibration curve is generated using recombinant human IL-18 standards with known concentrations.
• Mean absorbance values are plotted against IL-18 concentration on a semi-logarithmic scale.
• A four-parameter logistic (4PL) regression model is recommended for curve fitting.
• Sample concentrations are calculated by interpolation from the standard curve.
Analytical Performance
Dynamic Detection Range
• 10 – 2,000 pg/mL
Analytical Sensitivity
• Limit of Detection (LOD): ≤ 5 pg/mL
Precision
• Intra-assay CV: < 5%
• Inter-assay CV: < 5%
Selectivity & Specificity
The assay demonstrates high specificity for IL-18 with minimal cross-reactivity to related cytokines (IL-1β, IL-1α, IL-6, TNF-α) (< 1%).
Kit Components
Each kit contains sufficient reagents for up to 96 determinations:
• Antibody-coated 96-well microplate
• IL-18 standards (lyophilized, multiple concentrations)
• Biotinylated detection antibody
• Enzyme conjugate
• Assay buffer
• Wash buffer (10×)
• TMB substrate
• Stop solution
• Detailed assay protocol
Sample Collection & Handling
• Collect samples using standard laboratory procedures.
• Avoid repeated freeze–thaw cycles.
• Samples exceeding the highest standard should be diluted using assay buffer.
• Clarify samples prior to analysis if turbidity is present.
Storage & Stability
• Store all components at 2–8 °C.
• Do not freeze reagents unless explicitly stated.
• Unopened kits are stable until the stated expiration date.
Applications
• Inflammasome activation and innate immune signaling
• Gut-on-chip inflammation and epithelial stress modeling
• Host–microbiome immune crosstalk
• Infection and epithelial injury models
• Drug and biologic screening
• Biodevice calibration and benchmarking
