Ultrasensitive Antibody Detection by Agglutination-PCR (ADAP)

Area of Science:

• Biochemistry
• Molecular Biology
• Immunology

Background:

• Antibodies are crucial biomarkers for disease diagnosis.
• Current solid-phase antigen assays face challenges like antigen denaturation and epitope masking, particularly for conformational epitopes.
• Existing methods like radioimmunoassay have limitations in sensitivity, multiplexability, and reagent safety.

Purpose of the Study:

• To develop an ultrasensitive solution-phase method for antibody detection.
• To overcome the limitations of traditional antibody detection assays.
• To enable sensitive, multiplexed detection of challenging antibody biomarkers.

Main Methods:

• Developed antibody detection by agglutination-PCR (ADAP), a solution-phase assay.
• Utilized synthetic antigen-DNA conjugates that agglutinate upon antibody binding.
• Employed quantitative PCR (qPCR) for DNA quantification after ligation.

Main Results:

• ADAP achieves zepto- to attomole sensitivity with a 5-6 order dynamic range.
• Demonstrated 1000-fold increased sensitivity for anti-thyroglobulin autoantibodies compared to radioimmunoassay.
• Successfully showed multiplexed detection of multiple antibodies in a single experiment.

Conclusions:

• ADAP offers a simple, ultrasensitive, and broadly applicable method for antibody biomarker detection.
• The technique enhances sensitivity and multiplexing capabilities beyond current standards.
• ADAP presents new opportunities for antibody biomarker discovery and clinical diagnostics.