Protein biomarker

Go Beyond the Limits of Standard Assays

 

Accurate quantification of interferons and interleukins is critical for understanding immune regulation.

PBL Assay Science has developed ELISAs validated in human or mouse serum, plasma, and tissue culture media, demonstrating exceptional sensitivity, reproducibility across biological matrices, and publication-grade accuracy.

Near-basal sensitivity enables researchers to differentiate target analyte’s level between healthy state and disease state, allowing accurate assessment of disease onset, progression and therapeutic efficacy.

Key Highlights

  • Low-pg LLOQ (≈1–2 pg/mL) enabling quantification of low-abundance cytokines
  • Precision typically ≤10–20% CV, supporting robust longitudinal and comparative analyses
  • Validation in real clinical samples, including autoimmune, MS, and viral-infection cohorts
  • Consistent recoveries (~95–120%) and stable signal-to-noise ratios across biological matrices
  • Specificity with no cross-reactivity between IFN subtypes or across species (assay-dependent)
  • Broad cytokine coverage: IFN-α (12 subtypes), IFN-β, IL-15/IL-15Rα, IL-22, murine IFNs etc.
  • Matrix compatibility with serum, EDTA/heparin plasma, and tissue-culture media
  • Extensive citation record (>9 000 product citations) supporting the assay portfolio
  • Suitable for translational and mechanistic studies requiring reliable quantification at low abundance

Reliable Quantification in Low-Abundance Cytokines: LLOQ vs. LLOD

Why LLOQ is More Relevant than LLOD

LLOD (Lower Limit of Detection):

  • Lowest concentration producing signal above blank (tipically mean + 2-3 SD)
  • Often determined by extrapolation (dotten line) rather than actual measurement
  • Can detext presence but not reliably quantify (high CS > 20-30%)

LLOQ (Lower Limit of Quantification):

  • Lowest concentration with acceptable precision (CV ≤ 20% or ≤ 10%)
  • Provides reproducible, clinically meaningful quantitative results
  • Critial for monitoring low-level cytokines (IFN, ILS, etc.)

High-sensitivity immunoassays must reliably quantify a broad range of cytokines and interferons, across human and murine samples, free and complexed forms, and diverse biological matrices. PBL Assay Science portfolio is designed to meet these requirements, combining low-pg sensitivity, subtype coverage, and rigorous validation to support precise immune monitoring. The products below provide robust and consistent solutions for both fundamental and translational immunology studies.

Cytokine & Interferon Assay Portfolio 

Quantifies all 12 IFN-α subtypes in serum, plasma, or TCM

  • Range: 1.95 – 125 pg/mL
  • Precision: < 8 % intra-assay CV
  • Recovery: 95 – 120 % (serum & plasma)
  • Validation: autoimmune & influenza patient sera

Detect low-abundance IFN-beta without interference in the presence of soluble-IFNAR2 (sIFNAR2)

 

  • Range: 1.2 – 150 pg/mL | Assay time: ≈ 3 h 30 min
  • Spike recovery: 94 – 100 %
  • Precision: 2.5 % intra | 1.1 % inter
  • Specificity: no cross-reactivity with human IFN-α/γ/ω or murine IFNs
  • Quantification of IFN-β in serum, plasma (EDTA, Heparin, Citrate), or TCM
  • Independent validation by third-party CROs for quantifying IFN-beta in autoimmune immune disease sera, and trademarked IFN-beta therapeutics

 

Cytokine for immune and cell-therapy research

 

IL-15 / IL-15Ra ELISA:

  • One of the few ELISAs designed to detect both free IL-15 and the IL-15/IL-15Rα complex
  • Ultra-sensitive detection of basal IL-15 in healthy human serum

IL-22 ELISA:

  • Detects free IL-22 (not IL-22BP-bound)
  • Sensitivity : ≈ 1 pg/mL
  • Correlation: r = 0.83 vs Quanterix® ultra-sensitive digital platform

High-sensitivity detection of murine interferons

  • Mouse IFN-α: 14 subtypes (range 1.19 – 76 pg/mL)
  • Mouse IFN-β: range 0.94 – 60 pg/mL | < 10 % CV
  • Validated in: BALB/c, C57BL/6, CD-1 sera

Recombinant Cytokines & Proteins

We can also offer highly biologically active, pure and selective recombinant interferons and other inflammation-related cytokines: 

 

Main Research Areas

It Sounds Complex? That’s Exactly Why We’re Here

PBL Assay Science is built on the foundational work of Sidney Pestka, recipient of the U.S. National Medal of Technology and Innovation for pioneering interferon purification, cloning, and recombinant IFN therapeutics, and has contributed to interferon and cytokine biology for over 30 years, with > 9,000 product citations. Tebubio makes this expertise directly accessible to European researchers through localized scientific and operational support.

Let Us Help You Accelerate Your Research

PBL Assay Science is built on the foundational work of Sidney Pestka, recipient of the U.S. National Medal of Technology and Innovation for pioneering interferon purification, cloning, and recombinant IFN therapeutics, and has contributed to interferon and cytokine biology for over 30 years, with > 9,000 product citations.

Tebubio makes this expertise directly accessible to European researchers through localized scientific and operational support with our CRO services.

 

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