Question

What are three errors that could affect the outcome of any gel electrophoresis procedure?

1) Incorrect voltage applied
2) Contamination of the gel or buffer
3) Insufficient running time
4) Incorrect sample loading
5) Incomplete gel polymerization

Answer 1

Gel electrophoresis is a technique used to separate DNA fragments of different sizes. The DNA is loaded on a gel made of agarose and an electric current is applied. The DNA migrates towards the positive electrode and separates according to size. The gel is then stained to view the DNA fragments.

Step-by-step explanation:

Gel electrophoresis is a technique used to separate DNA fragments of different sizes. Usually, the gel is made of a chemical called agarose. Agarose powder is added to a buffer and heated. After cooling, the gel solution is poured into a casting tray. Once the gel has solidified, the DNA is loaded on the gel and electric current is applied. The DNA has a net negative charge and moves from the negative electrode toward the positive electrode. The electric current is applied for sufficient time to let the DNA separate according to size; the smallest fragments will be farthest from the well (where the DNA was loaded), and the heavier molecular weight fragments will be closest to the well. Once the DNA is separated, the gel is stained with a DNA-specific dye for viewing it.