Problem:
Agar is a relatively cheap substance from red algae. And it contains a saccharide agarose as well as a small amount of pectin.
Agar is used for culture plates as is, but for DNA gels a grade of agarose, I guess with the pectin removed. What happens when a gel is run in agar? i.e. why remove the pectin?
If you can guess, how is the pectin removed? I know there are enzymes that might do it, but not sure what's really used.
Please explain.