Physical property which determines how the DNA moves the gel is its size
Gel electrophoresis is a technique used to separate DNA fragments based on their size and charge
Electrophoresis involves running a current through a gel containing the molecules of interest
Based on their size and charge, the molecules will travel through the gel in different directions or at different speeds, allowing them to be separated from one another
Gels for DNA separation are often made out of a polysaccharide called agarose, which comes as dry, powdered flakes
When the agarose is heated in a buffer and allowed to cool, it will form a solid, slightly squishy gel
As the gel runs, shorter pieces of DNA will travel through the pores of the gel matrix faster than longer ones
After the gel has run for awhile, the shortest pieces of DNA will be close to the positive end of the gel, while the longest pieces of DNA will remain near the wells