Two part question:
I have always learned that when running a SDS-PAGE current is what decideds how fast the macro molecules migrate.
However, if the force excerted on a molecule is equal to charge times electric field.
Then wouldn't the speed at which the protein migrates depend more on voltage then current? As the the electric field is a measure of Voltage across an area.
Also, does this change based on the type of electrophoresis? (specifically, Agarose/DNA, and native page)
How do you calculate the time it would take for a molecule to reach the end of a gel based on the length of the gel and either the voltage or current?