Why is gel electrophoresis performed?

1 Answer
Feb 27, 2016

To visualize whether the targeted gene is amplified


Gel electrophoresis is done after amplifying DNA samples through Polymerase Chain Reaction (PCR). However, the targeted gene for your DNA samples cannot be validated only by observing with your naked eye since the material is minute and it appears like a droplet of substance (as a result of combining DNA samples with PCR cocktails). Therefore, amplified DNA fragment can be observed using gel electrophoresis (concentration of the gel depends on the size of the target base pair numbers) and is stained commonly with ethidium bromide and then viewed using a UV illuminator. Each preparation consists of a marker or ladder which will serve as your guide to estimate the size of the amplified DNA, indicated by a strong band. Sometimes degraded DNA samples can be observed when there's a smear, while samples contaminated with RNA have a laddering appearance.