Long before the powerful tool of electrophoresis was discovered, scientists only used gravity to manipulate DNA samples. Today, DNA electrophoresis has made a significant turning point in the world of genomic DNA, allowing DNA analysis methods, gene typing, and forensic investigations to speed up their processes and produce more accurate and reliable result.
DNA electrophoresis is a common technique in laboratories that is used to quantify and purify DNA samples through electric current. The scientists load samples into a gel matrix and apply electric current to separate the different-sized molecules. Unlike the larger molecules, the smaller molecules move more easily through the gel pores. The separation of DNA electrophoresis is based on size.
There are several gels that are used in DNA electrophoresis.
Agarose Gels
Because of its broad separation range and nontoxic property, this is the most commonly used gel matrix for separating nucleic acid. Depending on the concentration, agarose controls the size of the gel pore allowing the different sizes of nucleic acid to separate. During agarose gel electrophoresis, molecules of different charge and size separates as scientists apply electricity.
Polyacyramide gels
Providing very high resolution of DNA molecules, this gel is used for proteins ranging from the size of 5 to 2,000 kDa. It also resolves DNA molecules that have varying sizes under appropriate conditions. Because acrylamide is a potent neurotoxin in its liquid and powdered form, scientists take extra care when creating this type of gel matrix.
Starch
This is another non-toxic medium for electrophoresis made from hydrolyzed potato. Although it is a little a bit opaque compared to agarose and polyacyramide, starch separates nucleic acid according to charge and size under typical concentration of 5% to 10%.
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