It can be seen that less stretching force was needed for the present study compared to those of Hsieh and Liu [1]. Figure 8 Representative of DNA recoiling at different times (Δ t  = 5 s) for 1× TBE. Figure 9 Graphs showing (a) relaxation time vs viscosity and (b) μ vs . Figure 10 Comparisons with those of previous studies. Finally, data for mean stretch ratio were correlated in a power law from of Wi as x/L c = 0.17 Wi0.265, as indicated ASK inhibitor in Figure 11a. Teixeira et al.’s [14] and Smith et al.’s [15] results were also included in Figure 11a. Again, the present results show a large stretch with a definite Wi. Another correlation of mean stretch ratio as a function

of Pe is shown in Figure 11b. A straight line relation was found in the form of x/L c = 5.37 × 10−5 Pe + 0.18, and the initial stretch length was obtained as Pe equals zero in this study. Figure 11 Graphs showing (a) mean stretch ratio vs Wi

and (b) mean stretch ratio vs Pe. Conclusions DNA click here molecule dynamics in curved (semi-circle, 0° ≤ θ ≤ 180°) microchannels with different radii for five different buffer solutions of 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) with a variety of viscosity such as 40, 60, and 80 cP were extensively studied for 10−4 ≤ Re ≤10−3 and 5 ≤ Wi ≤12. The major findings drawn are as follows: 1. Radius effect was significantly noted with maximum stretch ratio occurring at the center of the semi-circle (θ = 90°) with a radius of 500 μm.   2. The oscillatory/recovery nature of the present stretching behavior was found.   3. The buffer solution type seems to have no significant influence on the stretch ratio, with no viscosity effect.   4. The correlation of x/L c was developed for parameters of Wi and Pe, respectively, with different functional relationships.   Authors’

information SSH is a professor at the Department of Mechanical and mTOR activation Electro Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan, Republic of China. FHW is a student working towards a master’s degree at the Department of Mechanical and Electro Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung, MycoClean Mycoplasma Removal Kit Taiwan, Republic of China. MJT is a student working towards a master’s degree at the Department of Mechanical and Electro Mechanical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan, Republic of China. Acknowledgements This work was supported by the National Science Council (NSC) of Taiwan under contract number NSC 101-2221-E-110-043-MY3. References 1. Randall GC, Schultz KM, Doyle PS: Methods to electrophoretically stretch DNA: microcontractions, gels, and hybrid gel-microcontraction devices. Lab Chip 2006, 6:516–525.CrossRef 2.