Other printing methods, such as capillary printing ( 8), microfluidic networks ( 9), evaporation ( 10), and degas-based printing ( 11), usually create continuous line-shaped patterns rather than dot-shaped patterns. In addition, it is difficult to increase concentration while keeping small footprints because multiple print runs are necessary. Techniques such as inkjet printing ( 6) or robotic contact pin printers ( 7) are widely used for patterning, but they may create varying footprint sizes due to contact angle. One option to simplify the system design is to prepattern the reagents so that biochemical reactions can run directly on-chip. A device that is considerably simpler will allow a transition of centralized laboratory testing to ubiquitous nucleic acid testing at small clinics, field, or home settings.
#Effect cho aegisub manual
It generally involves laboratory equipment (for example, thermal cyclers and centrifuges) that require external power sources, several hours of assay time, multiple manual sample preparation steps, or trained technicians ( 5).
Alternatively, real-time polymerase chain reaction (PCR), the current standard for highly sensitive quantitative molecular testing, is not well suited for low-cost field operation. Commercially available lateral flow test strips have many of these traits, but most current assays are qualitative, providing only positive/negative readouts ( 3), or require additional separate steps for DNA detection ( 4). Point-of-care medical diagnostic assays ( 1) are ideally low cost, portable, simple, rapid, and capable of quantitative nucleic acid detection ( 2). These autonomous, portable, lab-on-chip technologies provide promising foundations for future low-cost molecular diagnostic assays. This simple chip allows rapid quantitative digital nucleic acid detection directly from human blood samples (10 to 10 5 copies of methicillin-resistant Staphylococcus aureus DNA per microliter, ~30 min, via isothermal recombinase polymerase amplification). Furthermore, self-powered microfluidic pumping without any external pumps, controllers, or power sources is accomplished by an integrated vacuum battery on the chip. Second, a simplified sample preparation step is demonstrated, where the plasma is separated autonomously into 224 microwells (100 nl per well) without any hemolysis. First, we prepatterned the amplification initiator on the chip to enable digital nucleic acid amplification. We report an integrated microfluidic diagnostic device capable of on-site quantitative nucleic acid detection directly from the blood without separate sample preparation steps. Portable, low-cost, and quantitative nucleic acid detection is desirable for point-of-care diagnostics however, current polymerase chain reaction testing often requires time-consuming multiple steps and costly equipment. On-chip digital quantitative detection of MRSA DNA spiked in water. Isothermal heating using reusable instant heat packs.įig. RPA is more robust against plasma samples than LAMP and PCR.įig. Consistent loading with the vacuum battery system.įig. Compartmentalization of all 224 microwells can be done in 12 min.įig. Vacuum battery system versus conventional degas pumping.įig. Microwell filling speed versus vacuum strength.įig. Total plasma volume separated versus time.įig. Selective particle separation according to size.įig. Reliable compartmentalization with smaller microcliff gap designs.įig. Microcliff gap effect on spatial robustness.įig. Optical signal obstructed when blood cells are not removed.įig. Failure of blood separation without the microcliff.įig.
Digital plasma separation mechanism overview.įig. Vacuum charging and long-term storage.įig.
Exploded view of the simple construction.įig. Supplementary material for this article is available at įig.
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