What is the difference between 7-AAD and Propidium Iodide?

7-AAD and Propidium Iodide are both fluorescent, intercalating agents that can be used to stain cells and nucleic acids. The major difference between the two is that 7-AAD binds to double-stranded DNA by intercalating between base pairs in G-C-rich regions of DNA, while Propidium Iodide binds to DNA by intercalating between the bases with little or no sequence preference.