Which of the following is important for gel electrophoresis to work?

a. negatively charged nucleic acids to migrate through the gel

b. ethidium bromide to provide a means to visualize the DNA in the gel

c. Agarose or polyacrylamide to separate the DNA based on size

d. known molecular weight standards

e. all of the above are important for gel electrophoresis

e. all of the above are important for gel electrophoresis

Explanation:

Gel electrophoresis is the process of separating nucleic acids like DNA on the basis of their molecular size.

DNA is negatively charged due to its phosphate component so it is loaded at the negative pole (cathode) and it migrates to the positive pole (anode). The fragments separate on the basis of their size. Smaller fragments run faster while heavier ones run slower. Hence, it is also important to load a molecular weight standard so that we can find out the size of the sample bands by matching them with the standard bands size.

Ethidium bromide is a dye commonly used to visualize DNA bands. It is mixed with electrophoresis gel making solution. It intercalates within DNA and fluoresces when exposed to UV light so that the DNA bands are visible. Hence, all of these things are important for gel electrophoresis to work.