Suppose that a rod-like DNA molecule of length 250 nm undergoes a conformational change to a closed-circular (cc) form.

(a) Use the information in Problem 19.24 and an incident wavelength x = 488 nm to calculate the ratio of scattering intensities by each of these conformations, Imd/1ce' when 8= 20°, 45°, and 90°.

(b) Suppose that you wish to use light scattering as a technique for the study of conformational changes in DNA molecules. Based on your answer to part (a), at which angle would you conduct the experiments? Justify your choice.