Why agarose

Ethidium bromide can easily get into your cells. Human DNA is linear and stains well. This means that it can get into your DNA and untwist it. This is not a good thing, so make sure you are careful and protected when using ethidium bromide.

There are also safer and less toxic alternatives that you may be able to use. The phosphate molecules that make up the backbone of DNA molecules have a high negative charge. When DNA is placed on a field with an electric current, these negatively charged DNA molecules migrate toward the positive end of the field, which in this case is an agarose gel immersed in a buffer bath.

The agarose gel is a cross-linked matrix that is somewhat like a three-dimensional mesh or screen. The DNA molecules are pulled to the positive end by the current, but they encounter resistance from this agarose mesh.

The smaller molecules are able to navigate the mesh faster than the larger one, so they make it further down the gel than the larger molecules. This is how agarose electrophoresis separates different DNA molecules according to their size. The gel is stained with ethidium bromide so you can visualize how these DNA molecules resolved into bands along the gel.

Southern blotting may also be used as a visualization technique for agarose gels. For the final stage of the technique, gel imaging, you will need a gel documentation system as described above. Cleaver Scientific have a whole range of gel documentations to suite any budget or requirement. Take a look at our selection guide to find the best option for you and browse our product pages for more information.

To run a gel electrophoresis experiment you will require both the equipment and the reagents. The basic reagents required for agarose gel electrophoresis are:. Cleaver Scientific supplies all these reagents, include runSAFE, a non-toxic DNA stain that works with blue light for increased cloning efficiency and safety of use.

Concentrated DNA stain which when used in this form samples can be stained within minutes CleverGEL is a new environmentally friendly agarose suitable for routine analysis of nucleic acids using standard electrophoretic procedures All Rights Reserved. Company registration number: Skip to content. Agarose gel electrophoresis of DNA. How does it work? DNA has a distinct chemical structure, in which the nucleobases, the letters of the DNA code, are joined by a backbone of a sugar, deoxyribose, and a phosphate group.

This structure is shown in figure 1. As can be seen in the figure, the backbone of the DNA contains a negative charge for every nucleobase present, making the mass-to-charge ratio of DNA the same across different fragment sizes. Because of this negative charge, when we apply an electrical field to a solution containing DNA, the DNA molecules will migrate towards the positively charged electrode.

The Gel Matrix. In agarose gel electrophoresis we introduce a gel matrix, imagine several layers of sieves or netting, which the DNA migrates through along the voltage gradient towards the positive electrode. This matrix creates resistance and means that smaller molecules migrate more quickly while larger molecules migrate more slowly.

Figure 1: The chemical structure of DNA. The difference in migration rate is how we separate the different sizes of DNA molecule to determine their length. The pore size in this gel matrix is well suited to the separation of DNA and the speed of migration can be influenced by increasing or decreasing the percentage of agarose in the mixture.

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.

A narrow particle size distribution offers improved performance characteristics. The more uniform the beads, the more consistently the resin will perform, whether that be when packing the column or running your process. Most agarose-based resins on the market are produced using Batch Emulsification technology, first utilized around 50 years ago. This produces a relatively wide particle size distribution.

Purolite Life Sciences utilizes a patented manufacturing process called Jetting to produce uniform agarose beads for superior performance.

Why do we use agarose? What is agarose? Why is agarose used in Affinity Chromatography? Why is agarose used in Ion Exchange Chromatography? Does size matter? Pressure - the smaller the beads, and the narrower the size distribution, the higher the pressure-resistance of the beads.

In comparison, the larger the beads, the faster the flow rate in batch and FPLC experiments.