An integrated microfluidic device for influenza and other genetic analyses

Abstract

An integrated microfluidic device capable of performing a variety of genetic assays has been developed as a step towards building systems for widespread dissemination. The device integrates fluidic and thermal components such as heaters, temperature sensors, and addressable valves to control two nanoliter reactors in series followed by an electrophoretic separation. This combination of components is suitable for a variety of genetic analyses. As an example, we have successfully identified sequence-specific hemagglutinin A subtype for the A/LA/1/87 strain of influenza virus. The device uses a compact design and mass production technologies, making it an attractive platform for a variety of widely disseminated applications.

Microfabricated valveless devices for thermal bioreactions based on diffusion-limited evaporation

“…Recent trends in miniaturized bioreaction systems are to integrate bioreactions with sample preparation, fluidic handling, and product detection to produce systems that can rapidly, conveniently, and economically extract information from raw biological samples with greatly reduced cost. 4,7,11,12,[17][18][19][20]23,39 One technical challenge in miniaturizing bioreaction systems is preventing or reducing evaporative loss during thermocycling. Although mineral oils, [4][5][6][7][8][9][10][11][12][13][14][15][16]10,26 adhesive tapes 19,22 and silicone rubber gaskets 21 have all been used in miniaturized bioreaction devices, most integrated systems reported so far have used microvalves to prevent evaporative loss.…”

“…Although mineral oils, [4][5][6][7][8][9][10][11][12][13][14][15][16]10,26 adhesive tapes 19,22 and silicone rubber gaskets 21 have all been used in miniaturized bioreaction devices, most integrated systems reported so far have used microvalves to prevent evaporative loss. These microvalves seal the reaction chamber using pneumatically or mechanically actuated diaphragms, [7][8][9]11,15,[17][18][40][41][42][43] thermally actuated phase-change pistons, 12,19,39,44 or polyacrylamide gels. 19 Because all microvalves need to provide some kind of physical confinement and most require some kind of actuations to operate, they often add complexity to the microfabrication and fluidic operations.…”

Genotyping with microfluidic devices

“…The introduction of plastic chips made the utilization of microdevices even more cost effective, allowing such large-scale applications as clinical genotyping more feasible, even with single use/disposable chips. System integration led to the 'lab-on-a-chip' concept with such multiple functions as PCR amplification, restriction digestion, separation, fraction collection, etc [10]. The progress in the field was summarized in several reviews in the past few years [9,[11][12][13][14][15][16][17][18][19][20][21].…”

“…Separation was also carried out by conventional slab-gel electrophoresis and the results were in good agreement with those obtained by the microchip. Pal et al [10] designed an integrated genetic analysis device and tested for influenza viral strain subtyping using a PCR-RFLP method to distinguish the polymorphism in the hemagglutinin-coding region. All steps, including PCR, HpaI restriction digestion and electrophoresis separation were carried out on an integrated microchip.…”

HIV Diagnostics: Challenges and Opportunities

“…MLoCs can automate complex assays normally performed in a laboratory onto miniaturized, portable chips with minimal reagent requirements [33], and be utilized for sample processing, purification, blood fractioning or even basic PCR [30,113,114]. Antibody, antigen, nucleic acid and cell-counting assays that require multiple reagents, capture molecules, fluid handling and detection (e.g., fluorescence, surface plasmon resonance, surface-enhanced Raman scattering, mass spectrometry, electrophoresis and electrical conductance) modalities can be supported by the devices [115][116][117][118][119][120][121][122]. The challenge of ART monitoring was highlighted previously and there are many MLoCs in development that measure CD4 + T -cell counts out in the field without the need for sophisticated laboratory infrastructures [33,36,115,[123][124][125].…”