Strayer D R
Biochim Biophys Acta. 1979 Jan 26;561(1):69-76. doi: 10.1016/0005-2787(79)90491-x.
The effects of temperature and ethidium bromide on the banding of heat-denatured DNA was studied during equilibrium centrifugation in density gradients of NaI. Centrifugation at 10 degrees C prevents the partial renaturation of Escherichia coli DNA and Clostridium perfringens DNA that occurs at 20 degrees C. A centrifugation temperature of --5 degrees C is required to prevent renaturation of T7 phage DNA. Ethidium bromide decreases renaturation of Escherichia coli DNA during centrifugation at 20 degrees C and causes a small shift in the buoyant density of both denatured and native DNA. Equilibrium centrifugation at lower temperatures prevents DNA renaturation and permits increased utilization of the large buoyant density difference between native and heat-denatured DNA in gradients of NaI.
在碘化钠密度梯度平衡离心过程中，研究了温度和溴化乙锭对热变性DNA条带的影响。在10℃下离心可防止大肠杆菌DNA和产气荚膜梭菌DNA在20℃时发生的部分复性。需要-5℃的离心温度来防止T7噬菌体DNA复性。溴化乙锭在20℃离心过程中可降低大肠杆菌DNA的复性，并使变性和天然DNA的浮力密度都发生小的偏移。在较低温度下进行平衡离心可防止DNA复性，并能在碘化钠梯度中更多地利用天然和热变性DNA之间巨大的浮力密度差异。
