Thermo Scientific nucleic acid isolation products are optimized for high yield isolation of pure nucleic acids from a variety of biological sources. Discover our column-based GeneJET kits, and magnetic bead-based MagJET kits for high-throughput automated purification.

Thermo Scientific™ DNA ladders

We offer a broad selection of DNA ladders ranging from 10 bp to 48.5 kb for accurate analysis of double-stranded DNA in agarose or polyacrylamide gels.

Loading dyes

Loading dyes are essential for the preparation of DNA ladders, markers, and samples for loading on agarose or polyacrylamide gels. Depending on your DNA fragment of interest you can chose between different dyes that prevent DNA masking during gel exposure to UV light.

DNA loading dyes normally contain:

  • Glycerol to ensure that the sample easily sinks into the well
  • EDTA, which binds divalent metal ions that may interfere with electrophoresis. By complexing metal ions, EDTA also stops metal-dependent enzymatic reactions such as DNA degradation by nucleases
  • Tracking dyes (bromophenol blue, xylene cyanol FF, or orange G) to monitor the progress of electrophoresis by the migration of the dyes

DNA ladders prepared with various loading dye

Ordering information

Loading dye Description Quantity Catalog #
6X DNA Loading Dye Two-color tracking of DNA migration during electrophoresis 5 x 1 mL R0611
6X MassRuler DNA Loading Dye One-color tracking of DNA migration during electrophoresis 5 x 1 mL R0621
6X Orange DNA Loading Dye Two-color tracking of DNA migration during electrophoresis 5 x 1 mL R0631
6X DNA Loading Dye & SDS Solution Two-color tracking of DNA migration during electrophoresis 5 x 1 mL R1151


Agarose is a non-toxic polysaccharide extracted from seaweed. It is easy to use and is relatively inexpensive. For electrophoresis, high-quality agarose is crucial in order to obtain sharp bands. Standard high melting point agarose is used in routine DNA electrophoresis for separation of a wide range of DNA fragments. Low melting/gelling temperature agarose is recommended for rapid DNA gel extraction with the agarose digesting enzyme Agarase. It also commonly used for "in-gel" DNA treatment with enzymes or for bacterial transformation with nucleic acids directly after re-melting the gel.

Today you even have the convenience to use agarose in tablet format to omit messy weighing when preparing your gels. Try Thermo Scientific™ TopVision Agarose Tablets: high-quality, multipurpose agarose tablets in blister packaging.

Comparison of TopVision Agarose Tablets to traditional agarose powder

  Traditional agarose powder TopVision Agarose Tablets Advantage with TopVision Tablets 
Gel-to-gel variation High variability from weighing step Tablet form delivers higher consistency hand cast gel performance Consistent results
Hands-on time Time consuming weighing step <1 min. hands-on time— eliminate weighing step completely Time-saving
Manufacturing process Heavy dependency and use of organic solvents such as methanol, acetonitrile, DMF, heptane, etc. Organic solvent-free process—complete elimination of any organic solvent use Reduced environmental impact
Packaging Plastic bottles Tablet blister—bottle-free packaging, enhanced convenience and portability Convenient

Ordering information

Product Size Catalog #
TopVision Agarose 100 g R0491
TopVision Agarose 500 g R0492
TopVision Low Melting Point Agarose 25 g R0801
TopVision Agarose Tablets 200 tablets R2801
TopVision Agarose Tablets 1000 tablets R2802

Buffers for electrophoresis

The electrophoretic mobility of DNA molecules depends on the voltage and the composition of the electrophoresis buffer. For added convenience, choose one of our concentrated solutions of Thermo Scientific™ Tris-borate and Tris-acetate electrophoresis buffers.

Which electrophoresis buffer is right for you?

Size of the DNA Voltage Use this buffer
< 1 kb 5–10 V/cm TBE
1–5 kb 4–10 V/cm TAE or TBE
> 5 kb 1–3 V/cm TAE
Up to 10 kb, fast electrophoresis with Express DNA ladders Up to 23 V/cm TAE

Ordering information

Product Size Catalog #
50X TAE Buffer (Tris-acetate-EDTA) 1 L B49
10X TBE Buffer (Tris-borate-EDTA) 1 L B52