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Updated: Jan 10, 2026
A Flow Cytometry-Based Cell Surface Protein Binding Assay for Assessing Selectivity and Specificity of an Anticancer Aptamer
Published on: September 13, 2022
An integrated microfluidic system equipped with a shear force control device for optimized selection of
Yang-Sheng Shao1, Yi-Cheng Tsai1, Chih-Hung Wang1
1Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu, Taiwan.
Background:
Folate receptor alpha (FRα) is a key biomarker for ovarian cancer diagnosis. Aptamers with high affinity and high specificity targeting FRα were automatically screened herein on an integrated microfluidic system. By automating Systematic Evolution of Ligands by Exponential Enrichment (SELEX) on a single integrated microfluidic system (IMS) equipped with micropumps, microvalves, micromixers, and a micro nucleic acid amplification module, this system significantly improves efficiency compared to traditional SELEX methods.
Results:
The automated IMS completed the screening process in only 14 h, carrying out five positive selections (by using FRα), one negative selection (by using human serum albumin, bovine serum albumin, and fibrinogen), and one competitive selection round (by using blood) to enhance specificity. A custom-designed serpentine-shaped micropump was used to precisely control shear forces during washing, potentially contributing to the high affinity of the resulting aptamers. The top candidate displayed a dissociation constant as low as 23 nM, which is superior to aptamers obtained through conventional SELEX.
Significance:
These findings highlight the IMS's potential for efficiently discovering high-affinity and high-specificity biomolecular probes. The selected aptamer was successfully applied in a detection assay to quantify FRα, underscoring the system's promise for early ovarian cancer diagnosis.
