What is the purpose of gel electrophoresis?

Answer 1

The buffer is the medium through which the current flows. In the electrophoresis chamber, the anode and cathode are separated and the gel is placed between them. In order to close the circuit and generate the voltage which causes the migration, the entire chamber is filled with a conductive buffer. It is actually possible to perform electrophoresis without a buffer; however this requires a specially made electrophoresis chamber. In these chambers the electrodes actually contact the top and bottom of the gel eliminating the need for a conductive buffer to close the circuit.

SDS PAGE electrophoresis uses buffer not primarily as a conductor but for holding a desired pH, dissipating heat and providing SDS in excess in the case of denaturing gels. A gel would run without a buffer as the gel itself is a conductor but the currents involved would heat it to the point of decomposition. Also the volume of liquid in a gel does not allow for an adequate pH buffering system. Holding a pH is extremely important for reproducibility especially in native gels as the pH can change the charge on the peptide. It is true some gels do not require buffer but these are rare cases like isoelectric focusing.
the primary application of the buffer would be to conduct electricity,to form a closed circuit

Answer 2

In its simplest form a buffered solution contains a mixture of a weak acid and its conjugate base.

Buffer system in electrophoresis

1. Controls the pH of the gel,preventing damage to sample molecules and ,in certain cases, controlling the ionization state of the molecules.
2. second ,though no less significant function derives from the fact that the vast majority of current flowing through the electrophoresis gel is carried by the buffer ions.
3. For a homogeneous system life denaturing PAGE electrophoresis of DNA , in which the type and concentration of buffer in the tank and gel are the same,the buffer prevents wide swings in pH and controls the conductivity of the gel.
4. For the native electrophoresis of protein ,the buffer pH has the added function of controlling the state of ionization of the samples.

Answer 3

It is used as a matrix to fix or immobilize the proteins. When the gels are subjected to electrophoresis, the proteins will then move down the gel based on its MW.

Answer 4

Gel electrophoresis helps in separation of bands of DNA proteins depending on their respective rf values. This enables to establish the identity of an individual at molecular level.

Answer 5

The gel serves as a medium by which the DNA, protein, or dye can travel through. Its density will also separate the molecules based on size.

Answer 6

to separate the proteins, apparently.