Functional Biomarkers

Measure What Matters: Protein Interactions, Not Just Expression

QF-Pro brings clinical-grade FLIM-FRET to precision oncology. Measure protein-protein interactions at 1-10nm resolution and identify patients who will respond to therapy.

Longer Survival with Functional Biomarkers
135
Patients in Landmark JCO Study
24%
Patients Missed by Expression-Only Tests
1-10nm
Spatial Resolution

Expression Biomarkers Fail to Predict Response

Current companion diagnostics measure protein presence, not function. A protein can be highly expressed but inactive, or low-expressed but highly engaged.

Current Approach

Expression-Based Testing

Immunohistochemistry (IHC) measures how much protein is present, but cannot determine if proteins are actually interacting.

  • PD-L1 TPS ≥50% did NOT predict survival (P=0.162)
  • Cannot distinguish active vs. inactive proteins
  • Excludes patients who would respond to therapy
  • High false-negative rates in patient selection
QF-Pro Approach

Functional Biomarker Testing

FLIM-FRET technology measures actual protein-protein interactions at molecular scale.

  • PD-1/PD-L1 interaction strongly predicted survival (P<0.0001)
  • Detects functional engagement at 1-10nm
  • Identifies responders missed by IHC
  • Specificity: Does NOT predict chemo response

The Survival Difference is Unmistakable

In a retrospective study of 135 NSCLC patients treated with immune checkpoint inhibitors, QF-Pro measurement of PD-1/PD-L1 interaction fundamentally outperformed expression-based biomarkers.

P<0.0001
Statistical significance for functional biomarker prediction

Meanwhile, PD-L1 expression (TPS ≥50%) showed no significant correlation with survival (P=0.162). The functional biomarker identified 24% of patients who would have been excluded by expression-only criteria.

Median Overall Survival by PD-1/PD-L1 Interaction
High Interaction (iFRET Positive) 31 months
Low Interaction (iFRET Negative) 10 months

Source: Journal of Clinical Oncology, 2023. Sanchez-Magraner et al.
n=135 NSCLC patients treated with anti-PD-1/PD-L1 therapy.

Built on a Decade of Science

The QF-Pro platform is backed by extensive peer-reviewed research demonstrating clinical utility across multiple cancer types and biomarker targets.

View All Publications →

How QF-Pro Works

QF-Pro combines precision optics, time-resolved detection, and advanced algorithms to measure molecular interactions directly in tissue.

FLIM-FRET Detection

Measures fluorescence lifetime changes caused by energy transfer between interacting proteins.

Learn about FLIM →
🔬

1-10nm Resolution

FRET only occurs when proteins are within nanometers of each other—confirming direct molecular interaction.

Learn about FRET Efficiency →
🎯

Two-Site Specificity

Dual-antibody coincidence detection provides inherent specificity for true protein-protein interactions.

Learn about iFRET →

The Spatial Proteomics Glossary

A comprehensive reference covering FLIM-FRET technology, spatial proteomics, and their applications in cancer research. Built to support understanding of functional biomarkers.

140+
Curated Terms
14
Interactive Visualizations
Browse the Glossary
scientialux.bio/glossary_term/fret/

Förster Resonance Energy Transfer (FRET)

A distance-dependent quantum mechanical process where energy transfers non-radiatively from an excited donor fluorophore to an acceptor fluorophore. FRET efficiency is inversely proportional to the sixth power of the distance between molecules, making it exquisitely sensitive to molecular proximity at the 1-10nm scale.

Learning Paths

Structured journeys through key topics, with narrative context that explains why each concept matters and how they connect.

QF-Pro Primer

A 42-minute guided tour of FLIM-FRET functional proteomics — from the physics of energy transfer to clinical validation in 135 NSCLC patients. Interactive chapter guide with 40 topics linked directly to the glossary.

40 chapters 42 glossary terms 6 thematic acts
Watch the QF-Pro Primer →
1 The Problem — Why Expression Fails
2 The Technology — How FRET-FLIM Works
3 The Product — Violet 3.0 & Workflow
4 Research Applications
5 Clinical Validation — The JCO Evidence
6 Q&A — Expert Answers

Explore the Science

Interactive simulations help build intuition for the physics underlying functional biomarker measurement.

Ready to Learn More?

Explore the technology behind functional biomarkers and see how QF-Pro is transforming precision oncology.