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Oral: Isothermal Pathogen Detection


An Integrated Microfluidic Device for Rapid Plum Pox Virus Enrichment and Detection
S. ZHENG (1), Y. Yeh (1), V. Mavrodieva (2), W. Zhang (1), Z. Liu (2) (1) The Pennsylvania State University, U.S.A.; (2) USDA, APHIS, PPQ, CPHST-Beltsville Laboratory, U.S.A.

Rapid and sensitive detection is highly desirable for plant viral pathogens. However, plant samples with low virus concentrations pose significant challenges for early detection. We present a miniature disposable device, carbon nanotube size tunable enrichment microdevice (CNT-STEM), that is capable of rapidly concentrating and purifying plum pox virus (PPV) from leaf tissues. This microdevice enriches PPV in the sample by employing physical size-based exclusion. The device consists of patterned carbon nanotube (CNT) arrays and a microfluidics channel made of polydimethylsiloxane (PDMS). The microdevice captures PPV from homogenized leaf samples inside the CNT nanostructure while most of the host contaminants are removed. After elution, the PPV enriched sample is subjected to real-time RT-PCR. The procedure takes less than 2 hours, significantly faster than standard immunocapture virus enrichment procedure. The results showed that the microdevice increased analytical sensitivity of PPV real-time RT-PCR by up to 100 fold compared with the current USDA standard immunocapture sample preparation method. The microdevice could enable early detection of PPV by enriching virus particles directly from plant samples. The technology can also serve as a platform for enrichment of other plant viral pathogens.