Introduction:
Gel electrophoresis uses a gel matrix, typically made from agarose or polyacrylamide, to separate nucleic acids (DNA/RNA) or proteins based on their size, shape, and charge.
Procedure:
. Preparation of the Gel:
The gel is prepared by dissolving agarose or polyacrylamide in a buffer solution and allowing it to solidify in a casting tray.
Once set, a comb is used to create wells for sample loading.
2. Sample Application:
Samples, often mixed with a loading buffer that provides density and color for tracking, are loaded into the wells.
3. Electrophoresis:
The gel tray is submerged in a buffer solution within the electrophoresis chamber.
An electric field is applied, causing charged molecules to migrate through the gel matrix.
4. Visualization and Analysis:
Post-separation, the gel is stained with specific dyes (e.g., ethidium bromide for DNA) to visualize the separated bands.
The size of the molecules can be inferred using a molecular weight marker or ladder run alongside the samples.
Advantages:
1. Versatility:
Suitable for separating a range of biomolecules, especially DNA, RNA, and proteins.
2. Visualization:
Gels can be easily stained to visualize bands.
3. Flexibility in Resolution:
Choice of gel concentration can optimize resolution for different molecule sizes.
Disadvantages:
1. Gel Preparation:
Gels need to be prepared and set before use, which can be time-consuming.
2. Limitation in Sample Volume:
Only a limited volume of the sample can be loaded in each well.
3. Toxicity:
Polyacrylamide gels use toxic compounds (e.g., acrylamide).
