The Migration of Linear DNA Molecules in Agarose or Polyacrylamide

Question

The migration of linear DNA molecules in agarose or polyacrylamide gels occurs at a rate that is
A) independent of their size.
B) directly proportional to their size.
C) inversely proportional to their size.
D) dependent on the AT content.
E) dependent on the GC content.

Accepted Answer

The migration rate of linear DNA molecules in agarose or polyacrylamide gels is inversely proportional to their size, i.e., smaller molecules migrate faster than larger ones. This is because smaller molecules can move more easily through the gel matrix, experiencing less resistance from the gel structure. The migration rate is not dependent on the DNA sequence, such as AT or GC content, but only on the size of the DNA fragments.