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. 2014 Aug 7;9(1):382.
doi: 10.1186/1556-276X-9-382. eCollection 2014.

DNA stretching on the wall surfaces in curved microchannels with different radii

Shou-Shing Hsieh  1 , Fong-He Wu  1 , Ming-Ju Tsai  1
Affiliations

DNA stretching on the wall surfaces in curved microchannels with different radii

Shou-Shing Hsieh et al. Nanoscale Res Lett. .

Abstract

DNA molecule conformation dynamics and stretching were made on semi-circular surfaces with different radii (500 to 5,000 μm) in microchannels measuring 200 μm × 200 μm in cross section. Five different buffer solutions - 1× Tris-acetate-EDTA (TAE), 1× Tris-borate-EDTA (TBE), 1× Tris-EDTA (TE), 1× Tris-phosphate-EDTA (TPE), and 1× Tris-buffered saline (TBS) solutions - were used with a variety of viscosity such as 40, 60, and 80 cP, with resultant 10(-4) ≤ Re ≤ 10(-3) and the corresponding 5 ≤ Wi ≤ 12. The test fluids were seeded with JOJO-1 tracer particles for flow visualization and driven through the test channels via a piezoelectric (PZT) micropump. Micro particle image velocimetry (μPIV) measuring technique was applied for the centered-plane velocity distribution measurements. It is found that the radius effect on the stretch ratio of DNA dependence is significant. The stretch ratio becomes larger as the radius becomes small due to the larger centrifugal force. Consequently, the maximum stretch was found at the center of the channel with a radius of 500 μm.

Keywords: Curve effect; DNA stretching; Microchannel; μPIV.

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Figures

Figure 1
Figure 1
Fabrication of the present curved channel.
Figure 2
Figure 2
Schematic for the present measuring instruments.
Figure 3
Figure 3
Input voltage (DC) vs velocity for the present piezoelectric (PZT) micropump.
Figure 4
Figure 4
Flow characteristic of the present curved channel for a typical case (R = 500 μm).
Figure 5
Figure 5
DNA stretching and DNA molecule elongation. (a) Time history of DNA stretching at different Wi. (b) DNA molecule elongation length vs time.
Figure 6
Figure 6
Stretching ratio histogram for different buffers with different viscosities. (a) 40 cP, (b) 60 cP, and (c) 80 cP.
Figure 7
Figure 7
Comparisons with the related previous studies for DNA stretching.
Figure 8
Figure 8
Representative of DNA recoiling at different times (Δt = 5 s) for 1× TBE.
Figure 9
Figure 9
Graphs showing (a) relaxation time vs viscosity and (b) μ vsγ˙.
Figure 10
Figure 10
Comparisons with those of previous studies.
Figure 11
Figure 11
Graphs showing (a) mean stretch ratio vs Wi and (b) mean stretch ratio vs Pe.
See this image and copyright information in PMC

References

    1. Randall GC, Schultz KM, Doyle PS. Methods to electrophoretically stretch DNA: microcontractions, gels, and hybrid gel-microcontraction devices. Lab Chip. 2006;9:516–525. - PubMed
    1. Hsieh SS, Chen JH, Tsai CF. DNA molecule stretching through thermo electrophoresis and thermal convection in a heated converging–diverging microchannel. Nanoscale Res Lett. 2013;9:87. - PMC - PubMed
    1. Jo K, Chen YL, De Pablo JJ, Schwartz DC. Elongation and migration of single DNA molecules in microchannels using oscillatory shear flows. Lab Chip. 2009;9:2348–2355. - PMC - PubMed
    1. Gulati S, Liepmann D, Muller SJ. Elastic secondary flows of semidilute DNA solutions in abrupt 90° microbends. Phys Rev E Stat Nonlin Soft Matter Phys. 2008;9:036314. - PubMed
    1. Mai DJ, Brockman C, Schroeder CM. Microfluidic systems for single DNA dynamics. Soft Matter. 2012;9:10560–10572. - PMC - PubMed

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