Migration of DNA During Electrophoresis is Based

Question

Migration of DNA during electrophoresis is based
A) mostly on the size of the molecule, since the ratio of charge to mass is approximately the same, no matter how large the DNA is.
B) mostly on the charge of the molecule, since the ratio of charge to mass is approximately the same, no matter how large the DNA is.
C) mostly on the charge-to-mass ratio since this can vary greatly among pieces of DNA.
D) on parameters not understood well.

Accepted Answer

DNA migration during electrophoresis is primarily influenced by the size of the molecule. This is because DNA molecules carry a uniform negative charge due to their phosphate backbone, making the charge-to-mass ratio relatively constant across different sizes of DNA fragments. Therefore, the main factor affecting their migration speed through a gel is their size, with smaller fragments moving faster than larger ones.