Why is the largest DNA fragment band closest to the positive end of the gel?
Why is the largest DNA fragment band closest to the positive end of the gel?
Gel is porous, hence allows negatively charged DNA fragments to travel through, towards the anode (positive) end of gel. Obviously, the smallest hence the lightest DNA fragments from the sample would reach the positive end faster than the larger (and hence heavier) fragments.
What size fragments of DNA move the farthest in the gel why?
Gel electrophoresis can separate DNA fragments from about 200 to 50,000 base pairs (bp). Because DNA is a negatively charged molecule, the fragments move toward the positive electrode. Fragments travel through the gel according to their molecular weight – with the smallest fragments moving the greatest distance.