How are DNA fragments separated in gel electrophoresis?
DNA gel electrophoresis is a standard laboratory technique used to identify, quantify, and purify DNA fragments. DNA electrophoresis involves loading DNA samples into the wells of an agarose or acrylamide gel and subjecting it to an electric field.
DNA fragments have a net negative charge; when subjected to an electric field, the negatively charged nucleic acid fragments migrate towards the positive electrode. The length of DNA fragments is a primary factor that influences the rate of migration—shorter DNA fragments travel faster through the gel matrix than longer fragments. Therefore, DNA gel electrophoresis results in separation—or resolution—of DNA fragments based on size.
Thermo Fisher Scientific provides high-quality gels, reagents, and devices to support the DNA electrophoresis workflow.
Thermo Fisher Scientific’s precast gel technology allows rapid separation of DNA fragments and offers unparalleled convenience when compared to traditional DNA electrophoresis. Precast gels are available as Invitrogen E-Gel agarose gels, and Invitrogen Novex TBE polyacrylamide gels.
To craft a gel of choice, use UltraPure agarose powder or UltraPure acrylamide powder; these high quality gels allow for superior resolution and the formation of sharp bands. Agarose gels can also be cast with TopVision agarose tablets.
To determine the size and mass of double stranded DNA fragments in agarose and polyacrylamide gels, Thermo Fisher Scientific offers a broad selection of DNA ladders and markers ranging between 10 bp to 50 kb. The ladders are made from chromatographically purified DNA fragments and are available in standard and ready-to-use formats.
To detect DNA fragments in a gel, SYBR Safe DNA stains and ethidium bromide stains are available. SYBR Safe DNA gel stain and ethidium bromide are similar in detection sensitivity. However, SYBR Safe DNA gel stain has reduced toxicity and mutagenicity when compared to ethidium bromide.
To load and to monitor the migration of DNA samples, Thermo Fisher Scientific offers gel loading buffers including Invitrogen BlueJuice Gel and TrackIt loading buffers.
The series of UltraPure buffers and reagents, made from the high purity biochemicals, are designed for optimal performance of DNA gel electrophoresis.
Thermo Scientific DNA electrophoresis reagents include DNA ladders, buffers, dyes, and gel components. These laboratory staples are known for their purity and performance.
Thermo Scientific Owl Gel Electrophoresis systems offer horizontal and vertical gel casting running chambers and related accessories for routine electrophoresis including tanks, chambers, casters, plates, spacers, combs, power supplies, and other accessories.
The all-in-one Invitrogen E-Gel Power Snap Electrophoresis System is designed for fast and convenient E-Gel agarose gel electrophoresis, from DNA sample loading to gel image. With dry precast E-Gel agarose gel technology, you can run DNA samples in as little as 10 minutes and observe sample separation in real time. It is the only benchtop system that seamlessly integrates DNA sample separation and gel imaging into one workflow.
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