Standard ELISA gets researchers most of the way there. However, when the target exists at extremely low abundance — such as phosphorylated tau variants, scarce cytokines, or biomarkers that barely register on conventional assays — “most of the way” may not be enough.
Exazym® StreptaClick® Primer from Cavidi is a ready-to-use addition to standard streptavidin–biotin ELISA workflows. It brings BOLD signal amplification into a step that many laboratories already perform. No new instruments, no offline conjugation chemistry, and no complete protocol rebuild are required.
What Is Exazym® StreptaClick® Primer?
Exazym® StreptaClick® Primer is designed to enhance the sensitivity of standard sandwich ELISA assays by integrating into existing streptavidin–biotin workflows. It allows researchers to amplify assay signal while maintaining a familiar ELISA format.
- Compatible with standard streptavidin–biotin ELISA workflows
- No new instrumentation required
- No offline antibody conjugation needed
- No major protocol rebuild
- Designed for low-abundance biomarker detection
BOLD Signal Amplification Technology
The core technology behind Exazym® is BOLD, Binding Oligo Ladder Detection. This approach uses primer-conjugated secondary antibodies, DNA synthesis, and DNA-specific tertiary antibodies to amplify ELISA signal.
By increasing signal intensity, BOLD technology helps researchers push the lower limit of detection and quantification, making ultra-sensitive targets more accessible using established immunoassay infrastructure.
Application in Alzheimer’s Biomarker Detection
Annie Sernelin’s recent Master’s Thesis at Uppsala University focused on developing and optimizing a BOLD-amplified sandwich ELISA for detecting and quantifying Aβ in blood.
Through optimization of assay components and protocol parameters, including incubation time, blocking buffers, and antibody concentrations, background noise was reduced from 0.6 OD to 0.1 OD. Compared with a standard ELISA, BOLD amplification increased signal from approximately 2-fold to 10-fold as Aβ concentration increased.
The initial assay performance estimation showed strong potential, with an LLOQ of 1.42 pg/mL, placing it within the range of comparable products currently available on the market.
pTau181 Sandwich ELISA with BOLD Amplification
Exazym® BOLD signal amplification has also been applied to human pTau181 sandwich ELISA. pTau181 is an important Alzheimer’s-related neuro biomarker, and its detection in human plasma often requires sensitivity beyond what standard ELISA can deliver.
By applying BOLD amplification to an existing ELISA format, researchers can potentially achieve higher sensitivity without moving to a completely different assay platform.
Relevant Research Applications
- Alzheimer’s disease and neurodegenerative biomarker research
- pTau181, Aβ, and other low-abundance neuro biomarkers
- Scarce cytokine detection
- Improving the sensitivity of existing ELISA assays
- Ultra-sensitive sandwich ELISA development
- Clinical chemistry and diagnostic immunoassay research
Why Exazym® StreptaClick® Primer?
Many laboratories already rely on ELISA as a trusted, accessible, and cost-effective immunoassay platform. However, ultra-sensitive detection often requires additional instruments or complex assay redevelopment.
Exazym® StreptaClick® Primer offers a practical alternative. It enables signal amplification within the standard ELISA workflow, helping laboratories improve sensitivity while continuing to use familiar equipment and assay formats.
Conclusion
Exazym® StreptaClick® Primer is a practical signal amplification solution for researchers who want to extend the sensitivity of standard ELISA workflows. It is particularly relevant for low-abundance biomarkers such as pTau181, Aβ, phosphorylated tau variants, and scarce cytokines.
Dana Bioscience supports researchers interested in Exazym® products and Cavidi’s ultra-sensitive immunoassay technologies with product information, quotation support, and application review.