What is the 2nd step of gel electrophoresis?

Agarose gel is used (as a filter) to separate DNA fragments and potentially proteins. DNA fragments are placed in "wells" at one end of the agarose gel. Electric current is ran throughout the gel, forcing fragments to move away from the well. Occurs b/c phosphate groups in DNA carry a negative charge, making the DNA attracted to positive electrodes. Smaller fragments in the gel move easier than larger fragments, meaning they travel farther. Fragments of the same size move at the same speed and clump together.