Linker-free antibody conjugation for sensitive hydrogel microparticle-based multiplex immunoassay

Area of Science:

• Biotechnology
• Analytical Chemistry
• Materials Science

Background:

• Multiplex immunoassays enable simultaneous protein detection, crucial for medical diagnostics and biomarker discovery.
• Bead-based hydrogel microparticles offer high multiplex capacity and sensitivity, surpassing traditional ELISA.
• Current antibody conjugation relies on linkers vulnerable to hydrolysis and potential antibody damage.

Purpose of the Study:

• To develop a novel, linker-free antibody conjugation method for hydrogel microparticle immunoassays.
• To enhance the sensitivity and stability of hydrogel microparticle-based assays.
• To improve protein analysis for diagnostics and biomarker discovery.

Main Methods:

• Synthesized graphically encoded hydrogel microparticles using stop flow lithography.
• Reduced disulfide bonds in antibodies to create free thiols for direct hydrogel conjugation.
• Characterized optimal antibody reduction conditions and validated assay accuracy and specificity.

Main Results:

• Introduced a direct antibody-to-hydrogel conjugation method, eliminating the need for linkers.
• Achieved an average twofold improvement in assay sensitivity compared to linker-dependent methods.
• Demonstrated validated accuracy and specificity of the linker-free multiplex assays.

Conclusions:

• The linker-free conjugation method enhances hydrogel microparticle immunoassay sensitivity and stability.
• This approach offers a more robust platform for multiplex protein analysis.
• The improved method has significant implications for advancing medical diagnostics and biomarker discovery.