AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
Aerosol Test Particles with DNA Barcodes
RUTH N. UDEY, Elizabeth K. Wheeler, Brian R. Baker, A. Daniel Jones, George R. Farquar, Lawrence Livermore National Laboratory
Abstract Number: 182 Working Group: Homeland Security
Abstract Novel test particles containing DNA barcodes for airborne particle transport studies have been created that are universal, safe, and biodegradable. Materials currently available for indoor transport monitoring are limited as they may only be used for one test, after which the environment is contaminated. These new test particles are easily customizable by adding different DNA molecules as unique identifiers. These particles are also safe as they are constructed from FDA-approved food additives. These customizable aerosol test particles will provide vital experimental feedback for evaluating atmospheric and particle transport models.
These novel particles are principally made of FDA-approved, Kosher certified saccharide food additives, including glucono-delta-lactone, mannitol, trehalose, and maltodextrin. Several non-coding DNA templates were incorporated into the particles and were detected using highly specific quantitative real-time polymerase chain reaction (qRT-PCR) assays. Two different technologies, a modified commercial inkjet printer and a commercial spray dryer, were evaluated for particle production. The inkjet printer offered low-cost, rapid production of small quantities for optimization studies, and the spray dryer generated grams of particles appropriate for atmospheric studies. The physical properties of the particles were evaluated using SEM and APS. The number of DNA copies/particle on average was determined by collecting particles on a glass coverslip, counting them using microscopic image analysis, and eluting them into solution for qRT-PCR quantitation.
The physical properties of the saccharide materials (e.g. glass transition temperature) were optimized by combining the sugars in varying ratios in order to produce a free-flowing powder. The resulting test particles had spherical morphology and were size-tunable between 1 and 10 micrometers by varying solution concentrations and particle production parameters. The saccharides did not interfere with the accurate qRT-PCR quantitation of the DNA. The mean number of DNA copies/particle was also tunable depending on the amount of DNA added.
Prepared by LLNL under Contract DE-AC52-07NA27344.