Final answer:
To increase the separation of large DNA bands in agarose gel electrophoresis, you should decrease the percentage of agarose in the gel, as it will create larger pores and allow the larger DNA molecules to migrate more easily.
Step-by-step explanation:
Increasing Separation of Large DNA Bands in Agarose Gel Electrophoresis
To increase the separation of the large-sized bands in your DNA agarose gel, the correct choice is C- Decrease the % agarose. Lowering the percentage of agarose in the gel will result in a looser gel matrix, which will provide larger pores for the DNA fragments to travel through. Thus, larger DNA molecules will be able to migrate more easily, enhancing their separation. Using more TBE or adding more ethidium bromide will not change the pore size of the gel, and increasing the % agarose would make the gel's pore size smaller, which is better for separating smaller fragments, not larger ones.
Agarose gel electrophoresis is a technique used to separate DNA fragments by size. The agarose serves as a molecular sieve through which smaller DNA fragments can move more readily than larger ones. By altering the concentration of agarose, you can adjust the pore size of the gel and thereby change the resolution of different sized DNA fragments. A lower concentration gel will allow for high molecular weight DNA fragments to separate more distinctively.