Gel electrophoresis is a widely used technique in life science laboratories to separate macromolecules such as DNA, RNA, and proteins. In this technique, molecules are separated according to size and electrical charge. It is of utmost importance as the samples that need to be analyzed are then loaded into tiny wells on the gel with the help of a pipette.
Once the load is ready, an electric current of 50-150 V is applied. Now, the charged molecules present in the sample begin to migrate through the gel towards the electrodes.
The speed at which each molecule travels through the gel is called its electrophoretic mobility and is primarily determined by its net charge and size. Strongly charged molecules move faster than weakly charged ones.
Once the separation is complete, the gel is stained with a dye to reveal the separation bands. Ethidium bromide is a fluorescent dye commonly used in gel electrophoresis. The gel is soaked in dilute ethidium bromide solution and then placed on an ultraviolet transilluminator to visualize the separation bands. The bands are immediately examined or photographed for future reference, as they will diffuse into the gel over time.