What are the factors that affect electrophoresis?

Electrophoresis refers to the migration of charged particles under the influence of an electric field. These are the main factors that affect electrophoresis: 

1. Sample: The size, shape, and charge of the sample influence its rate of migration rate. The migration rate is inversely proportional to the size of the molecule. It is also affected by the shape of the sample. An increase in net charge speeds up migration. 
2. Buffer solution: The buffer stabilizes the pH of the supporting medium and affects the compound migration rate. Zwitterionic buffers are found to offer higher resistance to continuous electrolysis compared to standard buffers, particularly in capillary zone electrophoresis.
3. Applied voltage: The migration rate of the molecules being separated is affected by the applied voltages. DNA migrates faster through the gel when higher voltage is applied, but excessive voltage can cause the gel to melt or lead to smearing and distortion of DNA bands.
4. Frictional force: A frictional force hampers the mobility of charged molecules and slows them down. This frictional force is the measure of multiple factors including the hydrodynamic size and shape of the molecule, the viscosity of the butter, and the pore size of the medium in which electrophoresis occurs. 
5. Supporting media: The type of supporting media used impacts the migration rate of compounds. Inert media are preferable as the electrophoretic rate can be affected by molecular sieving, adsorption, and electro-osmosis processes that occur in the medium. Adsorption can cause tailing, leading to a comet-like movement rather than a band, reducing both the rate and resolution of separation.
6. Electroendosmosis: Electroendosmosis, or electro-osmotic flow, can alter electrophoretic separation. This occurs due to charged groups on the surface of the support medium, such as sulfate groups in agarose, carboxyl groups in paper, and silanol (Si-OH) groups on glass capillary surfaces. These ionized groups create an electrical double layer at the capillary wall/electrolyte interface. When a voltage is applied, cations in the electrolyte migrate toward the cathode, dragging the electrolyte solution with them, resulting in a net electroosmotic flow toward the cathode.