title: A portable, shock-proof, surface-heated droplet PCR system for Escherichia coli detection.
abstract: A novel polymerase chain reaction (PCR) device was developed that uses wire-guided droplet manipulation (WDM) to guide a droplet over three different heating chambers. After PCR amplification, end-point detection is achieved using a smartphone-based fluorescence microscope. The device was tested for identification of the 16S rRNA gene V3 hypervariable region from Escherichia coli genomic DNA. The lower limit of detection was 10(3) genome copies per sample. The device is portable with smartphone-based end-point detection and provides the assay results quickly (15 min for a 30-cycle amplification) and accurately. The system is also shock and vibration resistant, due to the multiple points of contact between the droplet and the thermocouple and the Teflon film on the heater surfaces. The thermocouple also provides real-time droplet temperature feedback to ensure it reaches the set temperature before moving to the next chamber/step in PCR. The device is equipped to use either silicone oil or coconut oil. Coconut oil provides additional portability and ease of transportation by eliminating spilling because its high melting temperature means it is solid at room temperature.
authors.affiliation: Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Scott V
authors.initials: SV
authors.lastname: Angus
authors.affiliation: Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Soohee
authors.initials: S
authors.lastname: Cho
authors.affiliation: Biomedical Engineering Graduate Interdisciplinary Program, The University of Arizona, Tucson, AZ 85721, USA.
authors.forename: Dustin K
authors.initials: DK
authors.lastname: Harshman
authors.affiliation: Viral Disease Division, Animal and Plant Quarantine Agency, Anyang-si, Gyeonggi-do 430-757, Republic of Korea.
authors.forename: Jae-Young
authors.initials: JY
authors.lastname: Song
authors.affiliation: Department of Agricultural and Biosystems Engineering, The University of Arizona, Tucson, AZ 85721, USA; Biomedical Engineering Graduate Interdisciplinary Program, The University of Arizona, Tucson, AZ 85721, USA. Electronic address: jyyoon@email.arizona.edu.
authors.forename: Jeong-Yeol
authors.initials: JY
authors.lastname: Yoon
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification*; D006361:Heating / Q000295:instrumentation*; D008904:Miniaturization; D016133:Polymerase Chain Reaction / Q000295:instrumentation*; D017422:Sequence Analysis, DNA / Q000295:instrumentation*; D000068997:Smartphone; D018511:Systems Integration; D013817:Thermography / Q000295:instrumentation; D014584:User-Computer Interface
chemical_list: D004269:DNA, Bacterial
keywords: 16S rRNA; Coconut oil; Contact angle; Polymerase chain reaction; Smartphone