Fig. 5.
Plots of energy potential as a function of toroid cross-sectional area for 3kbDNA condensed in various salt solutions. Probability distributions of toroid cross-sectional areas were calculated by using data shown in Fig. 3 and assuming a circular cross section for toroids. The resulting distributions were fit with asymmetrical χ2 distribution functions and converted to potential energy curves by using the Boltzman equation. The vertical energy scale for all curves is the same; however, units are not given because the absolute energy and energy difference between curves could not be determined.