Gel electrophoresis is a term that would be alien to many. However, it is one of the most important tools in many life science laboratories. It is a laboratory tool that can be utilized to separate DNA, RNA, and proteins, allowing scientists to recognize distinct patterns in their samples.
For gel electrophoresis, the samples are first placed in wells inside the gel. The gel is placed in a conducting fluid, and an electrical field is applied to the system. A negative electrode is applied to the end close to the wells, while the opposite end is charged positively by the positive electrode. This encourages the movement of nucleic acid molecules(DNA and RNA) towards the far end, as the presence of negatively charged phosphate groups induces a negative change on nucleic acid molecules. The gel used in gel electrophoresis, typically constructed of agarose, contains numerous porous holes through which the DNA can travel. As the process takes some time, when different DNA samples are placed in different wells, the rates at which they travel tend to differ, although the direction of movement shown by the molecules is the same. This is because the sizes of the DNA fragments differ and provide the basis for how scientists can differentiate between different DNA samples in gel electrophoresis.
The technique, although it may sound unrelatable to the majority, is a crucial component in many real-life examples. Some of these include the test for paternity and investigation into evidence from a crime scene. In the paternity tests, the DNA samples of the potential parent and child are taken and fragmented to make them small enough to be able to pass through the pores of the gel. Shining ultraviolet light(UV) on the gel reveals the distinct bands of the DNA. The number of shared bands between the two samples are studied, and if the number of shared bands is about half of the total number of bands, the adult is determined as the parent of the child. Conversely in forensic science, a total match between the band patterns produced from the suspect’s DNA and the DNA found from the evidence is required to convict the suspect.
Gel electrophoresis is a technique that has been used in numerous laboratory investigations since being developed in the 1930s, and has proved successful in many of them. Due to its accessibility and utility, being able to analyze nucleic acids and proteins using relatively simple methods, it continues to be a promising friend to biologists across the globe.
Jeehan (Jacob) Shin
Leader of LSBT Society
