A B S T R A C TInfluenza viruses with multiple subtypes have highly virulent in humans, of which influenza hemagglutinin (HA) is the major viral surface antigen. Simultaneous and automated detection of multiple influenza HA are of great importance for early-stage diagnosis and operator protection. Herein, a magnetism and size mediated microfluidic platform was developed for point-of-care detection of multiple influenza HA. With multiplex microvalves and computer program control, the detection process showed high automation which had a great potential for avoiding the high-risk virus exposure to the operator. Taking advantage of magnetism and size mediated multiple physical fields, multiple influenza HA could be simultaneous separation and detection depended on different-size magnetic beads. Using high-luminance quantum dots as reporter, this assay achieved high sensitivity with a detection limit of 3.4 ng/mL for H7N9 HA and 4.5 ng/mL for H9N2 HA, and showed excellent specificity, anti-interference ability and good reproducibility. These results indicate that this method may propose new avenues for early detection of multiple influenza subtypes.

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An automated detection device was constructed for H7N9 influenza virus hemagglutinin based on 3-D magnetophoretic separation and magnetic label.

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Background: The most convenient circulating tumor cells (CTCs) identification method is direct analysis of cells under bright field microscopy by which CTCs can be comprehensive studied based on morphology, phenotype or even cellular function. However, universal cell markers and a standard tumour cell map do not exist, thus limiting the clinical application of CTCs. Results: This paper focuses on an automatic and convenient negative depletion strategy for circulating tumour cell identification under bright field microscopy. In this strategy, immune microparticles (IMPs) are applied to negatively label white blood cells rather than the tumour cells, such that tumour cells can be directly distinguished under brightfield of the microscopy. In this way, all of the heterogeneous tumour cells and their phenotype properties can be retained for further cancer-related studies. In addition, a wedge-shaped microfluidic chip is constructed for heterogeneous CTC pre-purification and enrichment by size, thus significantly decreasing the interference of haematological cells. Additionally, all cell treatments are processed automatically, and the tumour cells can be rapidly counted and distinguished via customized cell analytical software, showing high detection efficiency and automation. This IMPs based negative cell labelling strategy can also be combined with other classic cell identification methods, thus demonstrating its excellent compatibility. Conclusion: This identification strategy features simple and harmless for tumour cells, as well as excellent accuracy and efficiency. And the low equipment demand and high automation level make it promise for extensive application in basic medical institutions.