Ethidium Bromide - (Feb/16/2008 )

How much concentration of ethedium bromide normally used in the lab

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Stock solutions of Ethidium bromide are typically 10 mg/ml. This is diluted 10,000x for gels, buffers, or staining solutions to around 1 ug/ml.

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we use 1.5ul of ethidium bromide (10mg/ml) for 50ml of agarose gel.

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How much concentration of Ethidium bromide solution for staining on gel after electrophoresis and how long?.

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2 options: either include the EtBr in the gel while still molten (no stain, no destain, but remember the EtBr runs in the opposite direction to the DNA, so the top of the gel ends up very bright, while the bottom is completely clear), or else run without EtBr, add it after the gel run and stain for 20-30 min then destain the same length of time, or until the background is low (but accept you'll have much larger volumes of dirty water afterwards).

As for amounts, we have stock solution of 10mg/ml, and I add 4 ul per 70 ml gel.

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