TY - JOUR T1 - Molecular diagnostics in a teacup: Non-Instrumented Nucleic Acid Amplification (NINA) for rapid, low cost detection of Salmonella enterica. JF - Chin Sci Bull Y1 - 2013 A1 - Kubota, Ryo A1 - LaBarre, Paul A1 - Weigl, Bernhard H A1 - Li, Yong A1 - Haydock, Paul A1 - Jenkins, Daniel M AB -

We report on the use of a novel non-instrumented platform to enable a Loop Mediated isothermal Amplification (LAMP) based assay for Salmonella enterica. Heat energy is provided by addition of a small amount (<150 g) of boiling water, and the reaction temperature is regulated by storing latent energy at the melting temperature of a lipid-based engineered phase change material. Endpoint classification of the reaction is achieved without opening the reaction tube by observing the fluorescence of sequence-specific FRET-based assimilating probes with a simple handheld fluorometer. At or above 22°C ambient temperature the non-instrumented devices could maintain reactions above a threshold temperature of 61°C for over 90 min-significantly longer than the 60 min reaction time. Using the simple format, detection limits were less than 20 genome copies for reactions run at ambient temperatures ranging from 8 to 36°C. When used with a pre-enrichment step and non-instrumented DNA extraction device, trace contaminations of Salmonella in milk close to 1 CFU/mL could be reliably detected. These findings illustrate that the non- instrumented amplification approach is a simple, viable, low-cost alternative for field-based food and agricultural diagnostics or clinical applications in developing countries.

VL - 58 IS - 10 U1 - http://www.ncbi.nlm.nih.gov/pubmed/25477717?dopt=Abstract ER - TY - JOUR T1 - Non-Instrumented Nucleic Acid Amplification (NINA) for Rapid Detection of Ralstonia solanacearum Race 3 Biovar 2. JF - Biol Eng Trans Y1 - 2011 A1 - Kubota, Ryo A1 - LaBarre, Paul A1 - Singleton, Jered A1 - Beddoe, Andy A1 - Weigl, Bernhard H A1 - Alvarez, Anne M A1 - Jenkins, Daniel M AB -

We report on the use of a non-instrumented device for the implementation of a loop-mediated amplification (LAMP) based assay for the select-agent bacterial-wilt pathogen Ralstonia solanacearum race 3 biovar 2. Heat energy is generated within the device by the exothermic hydration of calcium oxide, and the reaction temperature is regulated by storing latent energy at the melting temperature of a renewable lipid-based engineered phase-change material. Endpoint detection of the LAMP reaction is achieved without opening the reaction tube by observing the fluorescence of an innovative FRET-based hybridization probe with a simple custom fluorometer. Non-instrumented devices could maintain reactions near the design temperature of 63°C for at least an hour. Using this approach DNA extracted from the pathogen could be detected at fewer than ten copies within a 25 μL reaction mix, illustrating the potential of these technologies for simple, powerful agricultural diagnostics in the field. Furthermore, the assay was just as reliable when implemented in a tropical environment at 31°C as it was when implemented in an air-conditioned lab maintained at 22°C, illustrating the potential value of the technology for field conditions in the tropics and subtropics.

VL - 4 IS - 2 U1 - http://www.ncbi.nlm.nih.gov/pubmed/25485176?dopt=Abstract ER -