Low-Volume Label-Free Detection of Molecule-Protein Interactions on Microarrays by Imaging Reflectometric...

Area of Science:

• Biotechnology
• Analytical Chemistry
• Microfluidics

Background:

• Existing label-free microarray analysis methods like SPR have limitations in array size, temperature stability, and crosstalk.
• High-throughput protein interaction analysis is crucial for drug discovery and biological research.

Purpose of the Study:

• To develop and validate a novel high-throughput, label-free protein interaction analysis system for microarrays.
• To overcome the limitations of current technologies in terms of array size, sensitivity, and robustness.

Main Methods:

• Utilized 1λ-imaging reflectometric interferometry (iRIf) for label-free detection.
• Developed microfluidic flow cells in a microscope slide format for low reagent consumption.
• Implemented a system with high spatial (7 µm) and temporal (≤50 fps) resolution.

Main Results:

• Achieved high sensitivity with random noise <5 × 10^-5 and baseline drift <3 × 10^-6.
• Demonstrated potential for significantly larger array sizes (~40 spots/mm²) compared to current methods (~4 spots/mm²).
• Validated the system using biotinylated BSA-streptavidin and thrombin aptamer assays, yielding a KD of ~100 nM.

Conclusions:

• The developed iRIf system provides a robust, sensitive, and scalable platform for high-throughput protein interaction analysis on microarrays.
• This technology offers a significant advancement over existing methods, enabling larger and more efficient molecular interaction studies.