Electrophoresis is an analytical method in which a controlled electrical current is used in order to separate biomolecules according to their size to electric charge ratio, using a gelatinous matrix as the basis. When a mixture of ionized and net-charged molecules are positioned in an electric field, they experience an attractive force towards the pole that has opposite charge, allowing some time for positively charged molecules to move towards the cathode (negative pole) and those positively charged will move towards the anode (positive pole).
Gel electrophoresis is used in laboratories to classify and measure proteins or nucleic acids. After careful preparation, the samples are charged to one end of the gel, an electric current is applied, and the samples run to the positive end of the tray.
When did this technique begin to be used?
Electrophoresis began in earnest with the work of Arne Tiselius in 1931, and new separation processes and chemical analysis techniques based on electrophoresis continue to be developed in the 21st century. Tiselius, with the support of the Rockefeller Foundation, developed the “Tiselius apparatus” for motion limit electrophoresis. The method extended slowly until the advent of effective zone electrophoresis methods in the 1940s and 1950s, which used filter paper or gels to support the support media.
In the 1960s, gel electrophoresis methods became increasingly sophisticated, making it possible to separate biological molecules based on tiny physical and chemical differences, helping to boost the rise of molecular biology. Gel electrophoresis and related techniques became the basis for a wide range of biochemical methods, such as protein fingerprints, Southern hybridization and similar transfer procedures, DNA sequencing, and many more.
How does electrophoresis equipment work?
An electrophoresis device is a device that allows the separation of mixtures of particles with electric charge in solution, taking advantage of the different migration speed when an electric field is applied (electrophoresis). It is also used for the separation of DNA and proteins. With 4 outputs, the device has 4 measurement levels: from 0 to 500 mA, between 0 and 400 V, and from 0 to 1 mA between, 0 and 200 V.
Agarose gel electrophoresis is a procedure used in several areas of Biotechnology, it is an analytical procedure used in research, biomedical and forensic laboratories. Of the types of electrophoresis that exist, agarose gel electrophoresis is the most common and widely used method.
It is a separation method frequently used to analyze DNA fragments generated by restriction enzymes, PCR and is a convenient analytical method to determine its size in a range of 500-30,000 base pairs. It can also be used to separate other biomolecules such as dyes, RNA and proteins. There are different types of agarose gel electrophoresis but horizontal electrophoresis is the most commonly used to separate DNA molecules in agarose. Other types, such as vertical electrophoresis, are used to separate proteins and use polyacrylamide gels.
A current source is connected to the electrophoresis apparatus and an electric current is generated. The charged molecules of the sample will enter the gel through the wall of the sowing well. Molecules with a negative charge will migrate to the positive electrode (anode) while molecules with a positive charge will migrate to the negative electrode (cathode).
The buffer serves as a conductor of electricity and controls the pH, which is important for the stability of biological molecules. As the DNA has a negative charge at neutral pH it will migrate through the gel to the positive electrode during electrophoresis.
What considerations should you consider when applying this technique?
As with any scientific procedure, the possibility of human error and other sources of error exists and should be taken into consideration when interpreting the results. Taking into account the following: contamination of the sample Problems in the gel, loading of incorrect samples, problems in the electric current and problems in the visualization.
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