Gel electrophoresis is a way to separate and analysis of large molecules, such as proteins, by migrating a colloidal solution of them through a gel. It is also used to sort DNA strands according to the length.
It is used in a wide range of molecular research and can be used for genotyping or to identify clones that have the correct DNA insert.
How To Use Gel Electrophoresis To Separate DNA
Proteins and nucleic acid molecules can be separated and analysis through gel electrophoresis. it can separate according to the size or charge of these molecules. the gel which used in electrophoresis is called "agarose gel", and the DNA is separated by an electric current. The gel is located on a small plastic support "an Erlenmeyer flask" along with a salt water buffer. The longer or heavier the DNA fragment, the more slowly it will migrate in the gel. The DNA fragments, produced by PCR , are separated and viewed as bands on the gel. Each gel band contains thousands of DNA molecules of the same size.
the steps
1. The agarose gel has wells into which the DNA can be loaded by pipette. The gel which located on a small plastic support, is then flooded in a tank filled with liquid buffer and this tank has electrodes on either end. Near the wells is the negative pole, and to the opposite side of the wells is the positive pole.
2. as we know that DNA has a negative charge, so when there is a current, it will migrate towards the anode ( the positive pole).
Longer DNA fragments will move through the gel more slowly than the shorter ones. In the following figure, the different DNA bands are shown in blue, but in reality, the DNA is not visible as it moves through the gel so ..
3.there is Post migration step,the gel is removed and the bands gets dyed by ethidium bromide, so the banding patterns of the grouped DNA become visible, and can be analyzed. The ethidium bromide intercalates between DNA bases and causes the DNA fragments to glow when exposed to UV light.
Now the approximate lengths of the unknown DNA strands can be determined by comparing it to the DNA standard.
How To Use Gel Electrophoresis To Separate DNA
Proteins and nucleic acid molecules can be separated and analysis through gel electrophoresis. it can separate according to the size or charge of these molecules. the gel which used in electrophoresis is called "agarose gel", and the DNA is separated by an electric current. The gel is located on a small plastic support "an Erlenmeyer flask" along with a salt water buffer. The longer or heavier the DNA fragment, the more slowly it will migrate in the gel. The DNA fragments, produced by PCR , are separated and viewed as bands on the gel. Each gel band contains thousands of DNA molecules of the same size.
the steps
1. The agarose gel has wells into which the DNA can be loaded by pipette. The gel which located on a small plastic support, is then flooded in a tank filled with liquid buffer and this tank has electrodes on either end. Near the wells is the negative pole, and to the opposite side of the wells is the positive pole.
2. as we know that DNA has a negative charge, so when there is a current, it will migrate towards the anode ( the positive pole).
Longer DNA fragments will move through the gel more slowly than the shorter ones. In the following figure, the different DNA bands are shown in blue, but in reality, the DNA is not visible as it moves through the gel so ..
3.there is Post migration step,the gel is removed and the bands gets dyed by ethidium bromide, so the banding patterns of the grouped DNA become visible, and can be analyzed. The ethidium bromide intercalates between DNA bases and causes the DNA fragments to glow when exposed to UV light.
Now the approximate lengths of the unknown DNA strands can be determined by comparing it to the DNA standard.
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