03015nas a2200313 4500008004100000022001400041245015500055210006900210260000900279300001100288490000600299520199700305653002502302653001602327653002002343653003602363653004202399653002602441653002402467100001802491700002402509700001702533700001902550700001902569700002102588700001702609700002002626856005502646 2011 eng d a1932-620300aA simple, inexpensive device for nucleic acid amplification without electricity-toward instrument-free molecular diagnostics in low-resource settings.0 asimple inexpensive device for nucleic acid amplification without c2011 ae197380 v63 a

BACKGROUND: Molecular assays targeted to nucleic acid (NA) markers are becoming increasingly important to medical diagnostics. However, these are typically confined to wealthy, developed countries; or, to the national reference laboratories of developing-world countries. There are many infectious diseases that are endemic in low-resource settings (LRS) where the lack of simple, instrument-free, NA diagnostic tests is a critical barrier to timely treatment. One of the primary barriers to the practicality and availability of NA assays in LRS has been the complexity and power requirements of polymerase chain reaction (PCR) instrumentation (another is sample preparation).

METHODOLOGY/PRINCIPAL FINDINGS: In this article, we investigate the hypothesis that an electricity-free heater based on exothermic chemical reactions and engineered phase change materials can successfully incubate isothermal NA amplification assays. We assess the heater's equivalence to commercially available PCR instruments through the characterization of the temperature profiles produced, and a minimal method comparison. Versions of the prototype for several different isothermal techniques are presented.

CONCLUSIONS/SIGNIFICANCE: We demonstrate that an electricity-free heater based on exothermic chemical reactions and engineered phase change materials can successfully incubate isothermal NA amplification assays, and that the results of those assays are not significantly different from ones incubated in parallel in commercially available PCR instruments. These results clearly suggest the potential of the non-instrumented nucleic acid amplification (NINA) heater for molecular diagnostics in LRS. When combined with other innovations in development that eliminate power requirements for sample preparation, cold reagent storage, and readout, the NINA heater will comprise part of a kit that should enable electricity-free NA testing for many important analytes.

10aDeveloping Countries10aElectricity10aHot Temperature10aMolecular Diagnostic Techniques10aNucleic Acid Amplification Techniques10aPlasmodium falciparum10aReference Standards1 aLaBarre, Paul1 aHawkins, Kenneth, R1 aGerlach, Jay1 aWilmoth, Jared1 aBeddoe, Andrew1 aSingleton, Jered1 aBoyle, David1 aWeigl, Bernhard uhttp://microfluidicsciences.com/drupal/?q=node/20902404nas a2200277 4500008004100000022001400041245012900055210006900184260000900253300001100262490000900273520153100282653001901813653001201832653001101844653002401855653003601879653004201915100001801957700001701975700001901992700001902011700002102030700002002051856005502071 2010 eng d a1557-170X00aNon-instrumented nucleic acid amplification (NINA): instrument-free molecular malaria diagnostics for low-resource settings.0 aNoninstrumented nucleic acid amplification NINA instrumentfree m c2010 a1097-90 v20103 a

We have achieved the first complete, non-instrumented nucleic acid amplification test (NAAT) using a calcium oxide heat source thermally linked to an engineered phase change material. These two components alone maintain a thermal profile suitable for the loop-mediated isothermal amplification assay. Starting with computational fluid dynamics analysis, we identified nominal geometry for the exothermic reaction chamber, phase change material chamber, thermal insulation, and packaging. Using this model, we designed and fabricated an alpha prototype assay platform. We have verified the function of this multi-pathogen-capable platform with both fluorescent and visual turbidity indications using samples spiked with malaria DNA. Both the exothermically heated platform samples and samples heated on a Perkin-Elmer GeneAmp9600 thermocycler were first incubated at 62°C for 45 minutes, then heated to 95°C to terminate enzyme activity, then analyzed. Results from the exothermically heated, non-instrumented platform were comparable to those from the thermocycler. These developments will enable point-of-care diagnostics using accurate NAATs which until now have required a well-equipped laboratory. The aim of this research is to provide pathogen detection with NAAT-level sensitivity in low-resource settings where assays such as immunochromatographic strip tests are successfully used but where there is no access to the infrastructure and logistics required to operate and maintain instrument-based diagnostics.

10aDNA, Protozoan10aHeating10aHumans10aMalaria, Falciparum10aMolecular Diagnostic Techniques10aNucleic Acid Amplification Techniques1 aLaBarre, Paul1 aGerlach, Jay1 aWilmoth, Jared1 aBeddoe, Andrew1 aSingleton, Jered1 aWeigl, Bernhard uhttp://microfluidicsciences.com/drupal/?q=node/21501789nas a2200217 4500008004100000022001400041245008500055210006900140260001300209300001400222490000600236520111400242653004101356653002501397653001801422100002001440700002101460700001801481700001701499856005501516 2008 eng d a1473-019700aTowards non- and minimally instrumented, microfluidics-based diagnostic devices.0 aTowards non and minimally instrumented microfluidicsbased diagno c2008 Dec a1999-20140 v83 a

In many health care settings, it is uneconomical, impractical, or unaffordable to maintain and access a fully equipped diagnostics laboratory. Examples include home health care, developing-country health care, and emergency situations in which first responders are dealing with pandemics or biowarfare agent release. In those settings, fully disposable diagnostic devices that require no instrument support, reagent, or significant training are well suited. Although the only such technology to have found widespread adoption so far is the immunochromatographic rapid assay strip test, microfluidics holds promise to expand the range of assay technologies that can be performed in formats similar to that of a strip test. In this paper, we review progress toward development of disposable, low-cost, easy-to-use microfluidics-based diagnostics that require no instrument at all. We also present examples of microfluidic functional elements--including mixers, separators, and detectors--as well as complete microfluidic devices that function entirely without any moving parts and external power sources.

10aDiagnostic Techniques and Procedures10aDisposable Equipment10aMicrofluidics1 aWeigl, Bernhard1 aDomingo, Gonzalo1 aLaBarre, Paul1 aGerlach, Jay uhttp://microfluidicsciences.com/drupal/?q=node/218