Intelligent front-end sample preparation tool using acoustic streaming [report]

Erika J. Cooley, Jaime L. McClain, Jaclyn K. Murton, Thayne L. Edwards, Komandoor E. Achyuthan, Darren W. Branch, Paul Gilbert Clem, John Mueller Anderson, Conrad D. James, Gennifer Smith, Joseph Daniel Kotulski
2009 unpublished
We have successfully developed a nucleic acid extraction system based on a microacoustic lysis array coupled to an integrated nucleic acid extraction system all on a single cartridge. The microacoustic lysing array is based on 36º Y cut lithium niobate, which couples bulk acoustic waves (BAW) into the microchannels. The microchannels were fabricated using Mylar laminates and fused silica to form acoustic-fluidic interface cartridges. The transducer array consists of four active elements
more » ... for cell lysis and one optional BAW element for mixing on the cartridge. The lysis system was modeled using one dimensional (1D) transmission line and two dimensional (2D) FEM models. For input powers required to lyse cells, the flow rate dictated the temperature change across the lysing region. From the computational models, a flow rate of 10 µL/min produced a temperature rise of 23.2 ºC and only 6.7 ºC when flowing at 60 µL/min. The measured temperature changes were 5 ºC less than the model. The computational models also permitted optimization of the acoustic coupling to the microchannel region and revealed the potential impact of thermal effects if not controlled. Using E. coli, we achieved a lysing efficacy of 49.9 ± 29.92 % based on a cell viability assay with a 757.2 % increase in ATP release within 20 seconds of acoustic exposure. A bench-top lysing system required 15-20 minutes operating up to 58 Watts to achieve the same level of cell lysis. We demonstrate that active mixing on the cartridge was critical to maximize binding and release of nucleic acid to the magnetic beads. Using a sol-gel silica bead matrix filled microchannel the extraction efficacy was 40%. The cartridge based magnetic bead system had an extraction efficiency of 19.2 %. For an electric field based method that used Nafion films, a nucleic acid extraction 4 efficiency of 66.3 % was achieved at 6 volts DC. For the flow rates we tested (10 -50 µL/min), the nucleic acid extraction time was 5-10 minutes for a volume of 50 µL. Moreover, a unique feature of this technology is the ability to replace the cartridges for subsequent nucleic acid extractions. 5
doi:10.2172/993903 fatcat:566oov4n2bh5diu36alqbnxe34