title: An integrated microfluidic system for rapid screening of alpha-fetoprotein-specific aptamers.
abstract: The systematic evolution of ligands by exponential enrichment (SELEX) is a screening technique that involves the progressive selection of highly specific ligands via repeated rounds of partition and amplification from a large random pool of nucleic acid sequences. The products of this selection process are called aptamers and are either short single-stranded deoxyribonucleic acid (ssDNA) or ribonucleic acid (RNA) molecules with a high binding affinity to a large variety of target analytes. However, SELEX is a lengthy, labor-intensive, iterative process requiring multiple rounds of extraction and polymerase chain reaction (PCR) amplification. In order to address these problems, this study presents a new integrated microfluidic system consisting of a magnetic bead-based microfluidic SELEX chip and a competitive assay chip to automate the aptamer screening process. More importantly, the selected ssDNA sequences were confirmed to have a high affinity and specificity to the target molecules, using the developed competitive assay chip. With this approach, an aptamer specific to alpha-fetoprotein (AFP), which is a biomarker for liver cancers, has been successfully selected. The screened aptamer was used as a recognition molecule for AFP and has a linear detection range from 12.5 to 800 ng/mL, which was suitable for rapid clinical applications.
authors.affiliation: Department of Engineering Science, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Chao-Jyun
authors.initials: CJ
authors.lastname: Huang
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan.
authors.forename: Hsin-I
authors.initials: HI
authors.lastname: Lin
authors.affiliation: Department of Medical Laboratory Science and Biotechnology, National Cheng Kung University, Tainan 70101, Taiwan. Electronic address: hsieh@mail.ncku.edu.tw.
authors.forename: Shu-Chu
authors.initials: SC
authors.lastname: Shiesh
authors.affiliation: Department of Power Mechanical Engineering, National Tsing Hua University, Hsinchu 30013, Taiwan. Electronic address: gwobin@mail.ncku.edu.tw.
authors.forename: Gwo-Bin
authors.initials: GB
authors.lastname: Lee
mesh_terms: D052157:Aptamers, Nucleotide / Q000235:genetics; D001483:Base Sequence; D001667:Binding, Competitive; D014408:Biomarkers, Tumor / Q000032:analysis; D004277:DNA, Single-Stranded / Q000235:genetics; D004867:Equipment Design; D006801:Humans; D007118:Immunoassay; D008113:Liver Neoplasms / Q000737:chemistry; D046210:Microfluidic Analytical Techniques / Q000295:instrumentation / Q000379:methods*; D052156:SELEX Aptamer Technique / Q000295:instrumentation / Q000379:methods*; D000509:alpha-Fetoproteins / Q000032:analysis*
chemical_list: C097353:AFP protein, human; D052157:Aptamers, Nucleotide; D014408:Biomarkers, Tumor; D004277:DNA, Single-Stranded; D000509:alpha-Fetoproteins