What would you use to separate DNA fragments in gel electrophoreis ?

Options

A. Agarose gel
B. Bee wax
C. Paraffin wax
D. Lanolin

Answer

To separate DNA fragments in gel electrophoresis, the following steps are involved:

1. **Understanding Gel Electrophoresis**: Gel electrophoresis is a technique used to separate DNA fragments based on their size. Smaller DNA fragments move further through the gel compared to larger fragments.

2. **DNA Charge**: DNA is negatively charged due to its phosphate backbone. When an electric current is applied, the DNA fragments migrate towards the positive electrode.

3. **Matrix Selection**: The matrix used for separating DNA fragments in gel electrophoresis is agarose. Agarose is a polysaccharide extracted from seaweed and is commonly used for this purpose.

4. **Preparation of Agarose Gel**: To prepare the agarose gel, agarose powder is dissolved in hot water. The concentration of agarose determines the pore size of the gel, which affects the separation of DNA fragments.

5. **Casting the Gel**: Once the agarose is dissolved, it is poured into a mold to solidify, forming a gel with pores that act as a sieve for separating DNA fragments.

6. **Loading the Samples**: After the gel has solidified, DNA samples mixed with a loading dye are loaded into wells in the gel.

7. **Running the Gel**: An electric current is applied, causing the DNA fragments to migrate through the gel. Smaller fragments move faster and travel further than larger ones.

8. **Visualizing the Results**: After running the gel for a sufficient time, the DNA fragments can be visualized using a DNA stain, such as ethidium bromide, under UV light.

### Final Answer:
To separate DNA fragments in gel electrophoresis, you would use **agarose gel**.