Agarose gel what is

All gel docs will come with some form of illumination source, a filter to remove background light and a camera to detect the signal. Other than these basics there are a huge range of gel docs available starting from basic hood systems to systems with integrated PCs and touchscreens. Given the simple nature of this technique, scientists have been able to apply it to a wide range of studies, some of which are discussed below.

Probably the most frequent application of agarose gel electrophoresis is in molecular cloning. This is the construction of recombinant DNA molecules that are integrated into various organisms to create genetic modifications. The purpose of these modifications varies and can include production of a specific biomolecule, for example the production of insulin in pharmaceutical manufacturing. Other applications of molecular cloning include adding fluorescent protein fusions to existing cellular proteins to study their location in cells and creating new genetic circuits to carry out specific functions, such as breaking down toxins.

Whatever the desired end product is, electrophoresis is a key step in both the production and quality control of DNA fragments used in molecular cloning. Electrophoresis can be used to analyse the fragments created by polymerase chain reaction PCR or restriction digest, to ensure they are of the correct size. It can also be used to purify fragments, by running them on the gel and subsequently cutting out the band of interest and purifying the DNA from the agarose. Combined with PCR, agarose gel electrophoresis can be a powerful technique for identifying individuals based on their genetic code.

The human genome contains many regions of short repeats, the number of which vary uniquely between individuals. By targeting these regions with specific PCR primers, a profile of band on an electrophoresis gel corresponding to these regions can be created that is unique to that individual.

This technique, known as DNA fingerprinting, can be used in areas such as forensics for criminal investigations, genealogy and parentage testing. Electrophoresis can be used in a range of diagnostic tests, primarily in the screening of genetic disorders but also to identify abnormal proteins. DNA can be extracted from patients, or even from embryos for pre-implantation screening, and subject to PCR and agarose gel electrophoresis to confirm the presence of certain genes or genetic abnormalities.

Agarose gel electrophoresis can also be applied to some proteins, for example to study blood chemistry to determine suitability of certain medical treatments.

The wide range of applications, both academic and clinical make agarose gel electrophoresis an extremely important technique. Although the recent advent of next generation sequencing technologies has the potential to replace many of the current uses of agarose gels, their ease of use and versatility mean that this technique is likely to persist for the foreseeable future.

The popularity of agarose gel electrophoresis is partly due to its simplicity. The equipment required is easy to use and takes little training to operate correctly. The main components are discussed below. The gel tank, also called a gel box, is the main component of the horizontal agarose gel electrophoresis system. Generally, a gel tank will consist of a plastic container with a raised centre platform where the gel is places on a secondary support called a gel tray.

At either end of the tank, electrodes made from an inert conductive material, most commonly platinum, are fixed and wired to connectors to allow the connection to the power supply. Finally, a lid sits on the gel tank to prevent access to the chamber while high voltage is applied to the buffer. Cleaver Scientific manufactures gel tanks in a range of sizes for different applications and can custom manufacture systems for niche applications. Take a look at the selection chart and browse our product pages for more information.

Now available with 20 x 25cm, 20 x 20cm, 20 x 15cm or 20 x 10cm gel trays Run up to samples. To apply an electrical field to the gel, you will need an electrophoresis power supply.

These power supplies are specifically manufactured for electrophoresis applications and features very stable voltage and current outputs to prevent fluctuations in migrations speed. A good power supply with allow you to set either constant current or voltage depending on the requirement of the experiment, and more advanced supplies will allow programming of individual steps at different parameter values.

At Cleaver scientific we have a range of electrophoresis power supplies for all applications. Each power supply has a 2. Constant voltage, current and power options are available as well as pre-programmed or customer programmed conditions allowing users to save and repeat their experiments for exceptional reproducibility.

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. 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.

Shorter strands of DNA move more quickly through the gel than longer strands resulting in the fragments being arranged in order of size. The use of dyes, fluorescent tags or radioactive labels enables the DNA on the gel to be seen after they have been separated.

They will appear as bands on the gel. A DNA marker with fragments of known lengths is usually run through the gel at the same time as the samples. How is gel electrophoresis carried out?

Preparing the gel Agarose gels are typically used to visualise fragments of DNA. The concentration of agarose used to make the gel depends on the size of the DNA fragments you are working with.

The higher the agarose concentration, the denser the matrix and vice versa. Smaller fragments of DNA are separated on higher concentrations of agarose whilst larger molecules require a lower concentration of agarose.

To make a gel, agarose powder is mixed with an electrophoresis buffer and heated to a high temperature until all of the agarose powder has melted. Once the gel has cooled and solidified it will now be opaque rather than clear the comb is removed. Many people now use pre-made gels. The gel is then placed into an electrophoresis tank and electrophoresis buffer is poured into the tank until the surface of the gel is covered.

The buffer conducts the electric current. The type of buffer used depends on the approximate size of the DNA fragments in the sample. Preparing the DNA for electrophoresis A dye is added to the sample of DNA prior to electrophoresis to increase the viscosity of the sample which will prevent it from floating out of the wells and so that the migration of the sample through the gel can be seen.

The fragments in the marker are of a known length so can be used to help approximate the size of the fragments in the samples.

The prepared DNA samples are then pipetted into the remaining wells of the gel. When this is done the lid is placed on the electrophoresis tank making sure that the orientation of the gel and positive and negative electrodes is correct we want the DNA to migrate across the gel to the positive end.