It is assumed that a timely mass administration of antiviral drugs, backed by quarantines and social distancing, could contain a nascent influenza epidemic at its source, provided that the first clusters of cases were localized within a short time. However, effective routine surveillance may be impossible in countries lacking basic public health resources. For a global containment strategy to be successful, low-cost, easy-to-use handheld units that permit decentralized testing would be vital. Here we present a microfluidic platform that can detect the highly pathogenic avian influenza virus H5N1 in a throat swab sample by using magnetic forces to manipulate a free droplet containing superparamagnetic particles. In a sequential process, the viral RNA is isolated, purified, preconcentrated by 50,000% and subjected to ultrafast real-time RT-PCR. Compared to commercially available tests, the bioassay is equally sensitive and is 440% faster and 2,000-5,000% cheaper.
We have designed, fabricated and tested a real-time PCR chip capable of conducting one thermal cycle in 8.5 s. This corresponds to 40 cycles of PCR in 5 min and 40 s. The PCR system was made of silicon micromachined into the shape of a cantilever terminated with a disc. The thin film heater and a temperature sensor were placed on the disc perimeter. Due to the system's thermal constant of 0.27 s, we have achieved a heating rate of 175°C s−1 and a cooling rate of −125°C s−1. A PCR sample encapsulated with mineral oil was dispensed onto a glass cover slip placed on the silicon disc. The PCR cycle time was then determined by heat transfer through the glass, which took only 0.5 s. A real-time PCR sample with a volume of 100 nl was tested using a FAM probe. As the single PCR device occupied an area of only a few square millimeters, devices could be combined into a parallel system to increase throughput.
For whom the bell tolls: Surface‐functionalized superparamagnetic particles emulsified in mineral oil turn a free‐standing droplet into a flexible virtual laboratory with (sub)microliter volumes. By using magnetic forces, rare acute monocytic leukaemia cells are extracted from blood, preconcentrated, purified, lysed, and subjected to a real‐time PCR in minutes. The PCR works like a clockwork by rotating the droplet over different temperature zones.
We present a low-cost miniaturized fluorescence detection system for lab-on-a-chip applications with a sensitivity in the low nanomolar range; a built-in lock-in amplifier enables measurements under ambient light.
We have designed, fabricated and tested a real-time micro polymerase chain reaction (microPCR) system. It consists of a microscope glass cover slip placed on top of a micromachined silicon chip integrated with a heater and a temperature sensor. A single microL of a sample containing DNA was placed on the glass and encapsulated with mineral oil to prevent the evaporation of water, thus forming a virtual reaction chamber (VRC). The PCR chip required half a second to heat up from 72 to 94 degrees C and two seconds to cool from 94 to 55 degrees C, corresponding to a cooling rate of -20 K s(-1). The real-time PCR yield was determined by a fluorescence method. The melting curve analysis method as well as capillary electrophoresis was performed to determine the purity of the PCR product. As the glass slip is disposable, cross-contamination from sample to sample is eliminated. The total cost of running the PCR is given by the value of the cover slip and its treatment.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.