Inside Our Research Poster
Developing an ultra-sensitive cardiac troponin I ELISA is critical for early detection of myocardial infarction, yet standard methods typically have a limit of detection of only about 12.5 pg/mL. For researchers working on early cardiac injury detection, drug safety monitoring, or next-generation diagnostic assays, that’s not sensitive enough.
Our research team at Cavidi set out to change that. In a poster now available for download on BioTechniques, we present the full development of an ultra-sensitive cTnI sandwich ELISA powered by Exazym®’s BOLD signal amplification technology—achieving a 180-fold improvement in sensitivity.
The Approach
Building a high-performance troponin assay starts with the right antibodies. We evaluated multiple monoclonal antibody clones from HyTest, selecting capture and detector pairs that maximized signal while minimizing cross-reactivity with skeletal troponin I. A dual-capture strategy using two antibodies targeting distinct epitopes on cTnI proved essential for boosting sensitivity and ensuring specificity.
To integrate BOLD, we conjugated an oligo-dT primer to the detector antibody using click chemistry, then systematically optimized polymerase concentration, reaction time, buffer composition, and detection antibody ratios.
Cardiac Troponin I ELISA Results
In 25% cTnI-free serum at room temperature, the Exazym®-amplified ultra-sensitive cardiac troponin I ELISA achieved a limit of detection of 0.07 pg/mL—compared to 12.5 pg/mL for the standard ELISA. That’s approximately a 180-fold improvement
We also tested at 37°C—the operating temperature of many automated diagnostic systems—and observed a 50-fold sensitivity improvement, confirming that BOLD amplification translates to real-world conditions where automation matters.
Why This Matters
Normal circulating cTnI levels are typically below 20 pg/mL in men and 15 pg/mL in women, with a two- to three-fold increase potentially indicating early myocardial injury. An assay sensitive enough to quantify these subtle changes could help researchers detect cardiac damage earlier, improve monitoring of cardiotoxicity in drug development, and support the development of more precise diagnostic tools.
Importantly, this was all achieved on standard ELISA equipment. No proprietary instruments. No complex platform migrations. Just Exazym® kits added to a conventional sandwich ELISA workflow.
Explore the Full Data
- Download the poster on BioTechniques for the complete methodology, antibody selection process, calibration curves, and conclusions.
- Watch our troponin webinar replay where Dr. Peter Stenlund walks through the development process, optimization strategies, and live Q&A.
Discover how Exazym® can bring ultra-sensitive detection to your existing immunoassay workflows. Learn more about our products or contact us at support@cavidi.se.