Lien-Yu Hung

Rapid detection of influenza A virus infection utilizing an immunomagnetic bead-based microfluidic system

n Abstractn n This study reports a new immunomagnetic bead-based microfluidic system for the rapid detection of influenza A virus infection by performing a simple two-step diagnostic process that includes a magnetic bead-based fluorescent immunoassay (FIA) and an end-point optical analysis. With the incorporation of monoclonal antibody (mAb)-conjugated immunomagnetic beads, target influenza A viral particles such as A/H1N1 and A/H3N2 can be specifically recognized and are bound onto the surface of the immunomagnetic beads from the specimen sample. This is followed by labeling the fluorescent signal onto the virus-bound magnetic complexes by specific developing mAb with R-phycoerythrin (PE). Finally, the optical intensity of the magnetic complexes can be analyzed immediately by the optical detection module. Significantly, the limit of detection (LOD) of this immunomagnetic bead-based microfluidic system for the detection of influenza A virus in a specimen sample is approximately 5×10−4 hemagglutin units (HAU), which is 1024 times better than compared to conventional bench-top systems using flow cytometry. More importantly, the entire diagnostic protocol, from the purification of target viral particles to optical detection of the magnetic complexes, can be automatically completed within 15min in this immunomagnetic bead-based microfluidic system, which is only 8.5% of the time required when compared to a manual protocol. As a whole, this microfluidic system may provide a powerful platform for the rapid diagnosis of influenza A virus infection and may be extended for diagnosis of other types of infectious diseases with a high specificity and sensitivity.n n

Nucleus extraction from cells by optical-induced cell lysis on a continuous flow platform

Nucleus extraction from cells is essential for a variety of biomedical applications. In this study, we have developed a microfluidic platform integrated with optical-induced dielectrophoresis (ODEP) and optical-induced cell lysis (OICL) techniques combined with a hydrodynamic focusing module for continuous single cell membrane lysis and nucleus extraction. This OICL chip was formed with indium-tin-oxide (ITO) glass and a photoconductive (amorphous silicon, a-Si) layer. The light was illuminated on a-Si to induce a non-uniform electric field, which then generated a transmembrane potential across the cell membrane, thus causing the disruption of cell membrane without damaging the nucleus. Therefore, we could use an optical-induced non-uniform electric field to continuously and selectively lyse the cell membrane and then collect the nucleus by using the ODEP force using different light patterns. These techniques may become a promising method for molecular cytogenetic investigations and nucleus transfer.

Microfluidic platforms for rapid screening of cancer affinity reagents by using tissue samples

Cancer is the most serious disease worldwide, and ovarian cancer (OvCa) is the second most common type of gynecological cancer. There is consequently an urgent need for early-stage detection of OvCa, which requires affinity reagent biomarkers for OvCa. Systematic evolution of ligands by exponential enrichment (SELEX) and phage display technology are two powerful technologies for identifying affinity reagent biomarkers. However, the benchtop protocols for both screening technologies are relatively lengthy and require well-trained personnel. We therefore developed a novel, integrated microfluidic system capable of automating SELEX and phage display technology. Instead of using cancer cell lines, it is the first work which used tissue slides as screening targets, which possess more complicated and uncovered information for affinity reagents to recognize. This allowed for the identification of aptamer (nucleic acid) and peptide probes specific to OvCa cells and tissues. Furthermore, this developed system could be readily modified to uncover affinity reagents for diagnostics or even target therapy of other cancer cell types in the future.