Question

If you used gel electrophoresis to separate the same plasmid that has all three configuration of dna fragments, the supercoiled plasmid would move the fastest, while the multimer would move the slowest. why do the different plasmid configurations move the way they do through the gel?

Answer 1

This is because the supercoiled plasmid takes up less space (because it is compact) than the linear form, allowing it to move through the gel matrix faster. The gel matrix acts as a sieve: smaller DNA molecules migrate, through the pores, faster than larger ones.