Cat#ES1012 10ml(10mg/ml)

Description
The most commonly used stain for detecting DNA/RNA is Ethidium Bromide (EtBr). EtBr is a DNA intercalator, inserting itself into the spaces between the base pairs of the double helix. EtBr possesses UV absorbance maxima at 300 and 360 nm. Additionally, it can absorb energy from nucleotides excited by absorbance of 260 nm radiation. Ethidium re-emits this energy as yellow/orange light centered at 590 nm. The fluorescence of EtBr in aqueous solution is significantly lower than that of the intercalated dye. Ethidium Bromide Solution, Molecular Biology Grade (10mg/ml), is a fluorescent dye suitable for staining nucleic acids after electrophoresis or in cesium chloride gradients. The solution can be used to detect both double-stranded and single-stranded DNA.

Quality Control:
Each lot of Ethidium Bromide Solution is tested and certified to be free of DNase, RNase and protease activity.

Storage Conditions
Store at 22-25° C.

Detection of DNA/RNA using Ethidium Bromide
CAUTION: Ethidium Bromide Eis a potent mutagen. Handle only with gloves and proper precautions

Protocol: (add 5µ L EtBr to 100ml agarose gel solution)
1. Prepare 100 ml of agarose gel solution (concentration from 0.8-2.0%) in a 250 ml flask and mix it thoroughly. Place the flask in the microware, heat on high until the solution is completely clear and no small floating particles are visible (about 2-3 minutes).
2. Add 5µ L of EtBr to the gel solution. Swirl the flask gently to mix the solution and avoid forming bubbles.
3. While the gel solution cools below 50-60° C, pour it into the gel tray until the comb teeth are immersed about 1/4-1/2 into the gel solution.
4. Allow the agarose gel to cool until solidified. Load samples on the gel and perform electrophoresis.
5. Detect the bands under UV illumination.

Method II - Post Run Staining

1. Prepare enough 0.5µ G/ml EtBr in water or buffer to completely submerge the gel. This solution is stable for 1-2 months at room temperature in the dark.
2. After the run submerge the gel in the staining solution for 15-30 minutes (depending upon gel thickness).
3. Place the gel on plastic wrap on a UV light box and observe under 300nm illumination. Bands will appear bright orange on a pale orange background.

Notes:
(1) This protocol minimizes the amount of EtBr waste created with each gel run.
(2) Sensitivity is the same as method I, and may require destaining in water or 1mM MgSO4 to achieve the best sensitivity.
(3) In this method, bands become visible from the top and bottom of the gel as the dye diffuses into the matrix. High contrast results can often be achieved without destaining by soaking the gel until the top and bottom of the bands appear, and then leaving the gel to stand out of the staining solution for 15-30 minutes. During this time the stain will continue to diffuse into the gel, binding to the DNA at the expense of free dye. The result is a lower background without destaining.
(4) Always use plastic wrap under Ethidium stained gels, to avoid solarization damage to the surface of the transilluminator.