Electrophoresis: Difference between revisions

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This section should discuss new developments in the field. Don't hesitate to drop in brief mentions of processes or features you don't intend to discuss in depth.  By so doing you are planting seeds of articles which will eventually be developed by others.<ref>"New Directions for Flocculation," American Flocculation Society. 2006. Retrieved July 21, 2009 from [http://www.amflocsoc.org/future_devs.html http://www.amflocsoc.org/future_devs.html]</ref>
This section should discuss new developments in the field. Don't hesitate to drop in brief mentions of processes or features you don't intend to discuss in depth.  By so doing you are planting seeds of articles which will eventually be developed by others.<ref>"New Directions for Flocculation," American Flocculation Society. 2006. Retrieved July 21, 2009 from [http://www.amflocsoc.org/future_devs.html http://www.amflocsoc.org/future_devs.html]</ref>
== The Process ==
As shown in the diagram, the nucleic acids or proteins are loaded into the wells or depressions at one end on the eletrophoretic medium (also known as a ‘’gel’’). The apparatus also has two electrodes on either side of the eletrophoretic medium. The anode is positively charged while the cathode is negatively charged. When a power source connects the two electrodes the charged particles begin to migrate towards the oppositely charged electrode due to the electric potential field within the media <ref name=Harrison />.
The velocity of the particles are related to the electric field potential by the following equation:


==Generation of Heat in Electrophoresis Instrumentation==
==Generation of Heat in Electrophoresis Instrumentation==
As shown in the diagram, the nucleic acids or proteins are loaded into the wells or depressions at one end on the eletrophoretic medium (also known as a gel). The apparatus also has two electrodes on either side of the eletrophoretic medium. The anode is positively charged while the cathode is negatively charged. When a power source connects the two electrodes the charged particles begin to migrate towards the oppositely charged electrode due to the electric potential field within the media (1).
Due to the electric field in electrophoresis, the equipment generates a large amount of heat that needs to be dissipated for maximum efficiency. Since the gel’s viscosity and density changes with an increasing temperature, it is important to remove as much heat as possible from the apparatus otherwise the gel will melt. As a solution, increasing the surface area to volume ratio of the gel usually helps to dissipate the heat. For instance, capillary electrophoresis efficiently removes heat because of its high surface-area to volume ratio. Similar to native electrophoresis, this commonly used method maintains a constant electric field at a stable pH where the separation depends upon mobility <ref name=Harrison />.  


== Electrophoretic Mediums ==
== Electrophoretic Mediums ==

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Electrophoresis is a separation technique frequently used in the analysis of proteins and nucleic acids. The process known as electrophoresis, involves the migration of particles or molecules (in particular proteins, DNA, and RNA) through an electric field that separates them exclusively on the basis of their size or molecular weight. The direction the molecule moves depends on its charge while the rate of migration is affected by the size, shape, density of the gel and the strength of the applied current (5c). Electrophoresis is a very simple process and relatively quick with a high resolution. In addition electrophoresis is an extremely useful method to estimate the purity of a sample. The technique is also very sensitive to slight variations in molecular weight, size, and even shape of nucleic acids and proteins [1]. Electrophoresis can also be useful when it doesn’t affect the molecule’s structure or denature the protein Cite error: Invalid <ref> tag; invalid names, e.g. too many

The Process

As shown in the diagram, the nucleic acids or proteins are loaded into the wells or depressions at one end on the eletrophoretic medium (also known as a ‘’gel’’). The apparatus also has two electrodes on either side of the eletrophoretic medium. The anode is positively charged while the cathode is negatively charged. When a power source connects the two electrodes the charged particles begin to migrate towards the oppositely charged electrode due to the electric potential field within the media [1].


The velocity of the particles are related to the electric field potential by the following equation:


Generation of Heat in Electrophoresis Instrumentation

Due to the electric field in electrophoresis, the equipment generates a large amount of heat that needs to be dissipated for maximum efficiency. Since the gel’s viscosity and density changes with an increasing temperature, it is important to remove as much heat as possible from the apparatus otherwise the gel will melt. As a solution, increasing the surface area to volume ratio of the gel usually helps to dissipate the heat. For instance, capillary electrophoresis efficiently removes heat because of its high surface-area to volume ratio. Similar to native electrophoresis, this commonly used method maintains a constant electric field at a stable pH where the separation depends upon mobility [1].

Electrophoretic Mediums

Detection Techniques

Gel Electrophoresis of DNA and RNA

Gel Electrophoresis of Proteins

Native Electrophoresis

Denaturing Gel electrophoresis

Disadvantage/Advantage

Isoelectric focusing

Two-Dimensional Electrophoresis for Proteins

Two-Dimensional Electrophoresis for DNA and RNA

Blotting Techniques

Advantages & Disadvantages of Electrophoresis

References

  1. 1.0 1.1 1.2 Harrison, R. G., Todd, P., Rudge S. R., Petrides, D. P. (2003). Bioseparations Science and Engineering. New York, NY: Oxford University Press.