How does agarose separate molecules

The DNA race occurring in an electrophoresis gel is fair but it is an obstacle course. This is because the DNA molecules are forced to travel through the matrix of buffer filled spaces or pores that is created when the agarose gel is formed. The agarose gel provides a three dimensional lane. If you have any other comments or suggestions, please let us know at comment yourgenome. Can you spare minutes to tell us what you think of this website? Open survey. In: Facts Methods and Technology.

Gel electrophoresis is a technique commonly used in laboratories to separate charged molecules like DNA , RNA and proteins according to their size. Charged molecules move through a gel when an electric current is passed across it. An electric current is applied across the gel so that one end of the gel has a positive charge and the other end has a negative charge. The movement of charged molecules is called migration. Molecules migrate towards the opposite charge.

A molecule with a negative charge will therefore be pulled towards the positive end opposites attract! The gel consists of a permeable matrix, a bit like a sieve, through which molecules can travel when an electric current is passed across it. Smaller molecules migrate through the gel more quickly and therefore travel further than larger fragments that migrate more slowly and therefore will travel a shorter distance.

As a result the molecules are separated by size. DNA is negatively charged, therefore, when an electric current is applied to the gel, DNA will migrate towards the positively charged electrode. Running the gel. Figure 2: Running of an agarose electrophoresis gel. Visualising the DNA. Figure 3: Image of an agarose gel stained with Ethidium Bromide and captured using a gel documentation system. Video Demonstration.

Molecular Cloning. Genetic Fingerprinting. Equipment for Agarose Gel Electrophoresis. Figure 4: Diagram of a gel tank with all components. Find out more.

Power Supply. Gel Documentation System. Reagents for Agarose Gel Electrophoresis. Gel Loading Dye 10x bromophenol blue. Gel Extraction Tips Eliminates scalpel damage to transilluminator or gel tray.

Agarose, Low Melting point DNA Ladders Available in 6 molecular weight ranges. Sign up for News and Offers. Sign Up. Facebook Twitter Youtube Linkedin. Latest News. Customisable Glove Boxes. Custom Manufactured Lab Equipment.

Introducing IdentiTapes. Reagents and Chemicals for Western Blotting. The Complete Solution for Western Blotting. What is electrophoresis? Web Scientific has now joined our sister site Thistle Scientific! While polyacrylamide gel electrophoresis is typically performed in a vertical apparatus, agarose gel electrophoresis is conducted in a horizontal configuration to provide better support at low agarose concentrations. This produces less distortion collapse of the gel and of the DNA bands during electrophoresis.

The submarine system, in which the gel is completely submerged in buffer, is the easiest to operate. The cathode end of the electrophoresis chamber then becomes basic, and the anode end becomes acidic. Use of a buffer system is therefore needed. Besides their excellent buffering capacity, they also aid in DNA mobility through the gel matrix.

These markers are test standards having properties resembling nucleic acids. The unique dye marker mix contains 6 dye markers that will migrate at different molecular weights, providing a range of colored bands visible in ordinary room light. The following reference chart indicates the approximate bps with which the individual tracking dyes migrate at different agarose gel concentrations. Chromatrack TM Migration Chart in bps. Dye 0. View the video presentation on Agarose gel Electrophoresis.

Locate and check that you have all of the following materials to perform agarose gel electrophoresis:. On reagent shelf:. In refrigerator:. In gel electrophoresis drawer:. Place the weighed-out agarose in a ml beaker. The stock bottle is in the refrigerator. Store buffer in a plastic storage bottle.

Add 30ml of the 1X TBE to agarose in the beaker.