Difference between agarose and polyacryamide

Answer 1

Agarose and polyacrylamide are both types of gels that are used in electrophoresis techniques, but they have different compositions and characteristics.

1. Composition:
- Agarose: Agarose is a polysaccharide extracted from seaweed. It forms a matrix of long, unbranched chains that can be easily manipulated and has a higher pore size compared to polyacrylamide.
- Polyacrylamide: Polyacrylamide is a synthetic polymer formed by the polymerization of acrylamide monomers. It forms a network of cross-linked chains that create a fine meshwork with smaller pore sizes compared to agarose.

2. Resolution:
- Agarose: Agarose gels are commonly used for separating large DNA molecules (over 1 kb) or molecules with higher molecular weights. It has a lower resolution compared to polyacrylamide gels.
- Polyacrylamide: Polyacrylamide gels are used for separating smaller DNA molecules (under 1 kb) or proteins. They offer higher resolution due to the smaller pore sizes in the gel.

3. Handling:
- Agarose: Agarose gels are easier to handle and cast, as they can be prepared by simply dissolving agarose powder in buffer and heating it to create a gel.
- Polyacrylamide: Polyacrylamide gels require more preparation, as they need to be polymerized using a mixture of acrylamide and a cross-linking agent in the presence of a catalyst. They are more complex to prepare and handle compared to agarose gels.

4. Safety:
- Agarose: Agarose gels are considered safer to use as they are non-toxic and non-carcinogenic.
- Polyacrylamide: Polyacrylamide gels are potentially hazardous due to the toxic nature of acrylamide monomers. Proper safety precautions need to be taken when handling polyacrylamide gels.

In summary, agarose gels are easier to work with and are suitable for larger molecules, while polyacrylamide gels offer higher resolution and are more suitable for smaller molecules. The choice between agarose and polyacrylamide gels depends on the specific requirements of the experiment.