g You have decided to add ethidium bromide directly to your agarose solution before you pour you gel. You have a stock solution of 6 mg/ml and you want a final concentration of 0.5 g/ml in your 50 ml agarose solution. Calculate how much of the stock solution you will need to make add to the agarose solution to give you a final concentration of 0.5 g/ml.

4.17mL of the stock solution of ethidium bromide must be added in the 50mL agarose solution

Explanation:

You want to dilute the ethidium bromide from 6mg/mL to 0.5mg/mL, that is:

6mg/mL / 0.5mg/mL = 12 times the stock solution must be diluted.

As the final volume of the solution is 50mL, you must add:

50mL / 12 =

4.17mL of the stock solution of ethidium bromide must be added in the 50mL agarose solution

i would say b

explanation:

but i think i would need more information than that