Ethidium Bromide Solution (10 mg/mL)

For use in agarose gels:

- Add ethidium bromide to melted agarose to a final concentration of 0.5 µg/mL. Do not melt agarose that already contains ethidium bromide.

For staining agarose gels after electrophoresis:

- You can stain gels that have been run in the absence of ethidium bromide by covering the gel in 0.5 µg/mL ethidium bromide in water and gently agitating for 10 to 30 minutes.
- If necessary, gels can be destained by shaking in H2O for an additional 30 minutes. To stain RNA gels, you should minimize staining time and definitely include a destaining period.

Ethidium bromide can be used to detect ssDNA, RNA, and dsDNA. This fluorescent dye intercalates between the stacked bases of nucleic acids, and exhibits an increased fluorescence at 590 nm. Ethidium bromide can detect down to ~1-10 ng/band of dsDNA in an agarose gel.