Ethidium Bromide Fluorescence

[Bryant Fujimoto]

billatkins at bigfoot.com (Bill Atkins) writes:

>Why does ethidium bromide only fluoresce in the prescense of DNA?

>Thanks,
>Bill

The excited state of ethidium can be quenched by a transfer of
a proton to the solvent.  This occurs more efficiently in H2O
than D2O, and more efficiently in either case than when the
ethidium is intercalated in DNA.

Olmsted and Kearns (1977), "Mechanism of Ethidium Bromide
Fluorescence Enhancement on Binding to Nucleic Acids",
Biochemistry 16(16), 3647-3654.

Bryant Fujimoto
fujimoto at u.washington.edu
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