Tris-Borate-EDTA, or TBE, is commonly made as a 5x solution. What volumes of 5x TBE and water are required to make 500 ml of a 0.5x solution, which is often used in electrophoresis?

To make a 500 ml of a 0.5x TBE solution, you need to dilute the 5x TBE solution. Using the formula C1V1 = C2V2, where C1 is the concentration of the stock solution (5x), V1 is the volume of the stock solution, C2 is the desired concentration (0.5x), and V2 is the final volume you want to make (500 ml), we can calculate the volumes needed. C1V1 = C2V2 (5x)V1 = (0.5x)500 ml V1 = (0.5x)500 ml / 5x V1 = 50 ml Therefore, you need 50 ml of 5x TBE solution and 450 ml of water to make 500 ml of a 0.5x TBE solution.