; Heating effect on the histogram of DNA stretch ratio Figure 9 shows the DNA histogram of the stretch ratio without the electric field applied at the inlet region. The heating effect was clearly noted as the maximum extension length went from about 2.5 μm at 25°C to 6.5 μm at 55°C. In addition, 85% of the DNA molecules (≃85%) were at 1.5 μm at 25°C versus 40% at 5.5 μm, even with no external electric field employed. The stretching was partly due to thermal expansion of the DNA molecules (≤10%) and partly selleck kinase inhibitor because of thermophoresis (≥90%). Each contribution (10% versus 90%) can be calculated based on a measured

thermal expansion coefficient in Figure 8 and obtained. Figure 9 Histogram of DNA length without electric field strength at different temperatures. (a) 25°C, (b) 35°C, (c) 45°C, and (d) 55°C. Moreover, when electric strength was applied, the stretch ratio was enhanced.

Figure 10 shows respectively the corresponding results at different regions Selleckchem Wortmannin (inlet/middle) with different temperatures at E x = 10 kV/m and Deborah number (De) = 2.3. The effect of the position either at the inlet/or middle region can be seen. At the downstream middle region, the DNA molecules seemed to be further stretched, and most significantly, more DNA molecules were found at a larger stretch ratio, for instance, 10% (inlet) versus 20% (middle) at 55°C and De = 2.3 for a stretch ratio of 0.4. Figure 10 Histogram of the stretch ratio of DNA molecule after deducting the thermal expansion effect. At E x = 10 kV/m at different temperatures.

Inlet region: (a) 25°C, (b) 35°C, (c) 45°C, and (d) 55°C. Middle region: (e) 25°C, (f) 35°C, (g) 45°C, and (h) 55°C. Stretching force distribution Extracting the data from Figure 10, the maximum extension distribution was LY333531 order deduced to be a function of the stretching force. The stretching portions of the force-extension curves as a function of temperature are shown in Figure 11, in which the DNA molecule maximum extension length versus hydrodynamic force after deducting the thermal effect can be drawn and compared with those from the well-known force law of the wormlike-chain (WLC) model. The stretching force clearly decreased as the temperature increased due to thermal convection and/or thermophoresis, as evidenced Fossariinae by the thermal convection velocity distributions, as shown in Figure 4b and especially in Figure 5a,b,c,d,e,f. With the thermal expansion effect deducted, the different temperature results were shown in Figure 11a. As expected, the temperature effect had a significant influence on extension. Unlike those in Hsieh et al. [2] or Hsieh and Liou [3], the present stretching behavior at a temperature of 55°C changed following the evolution of double strand, transition, and single strand, based on CLSM in situ observation. Even so, similar linear dependence behavior was still found with different slopes.