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Merck

Agarose

Close up of ultraviolet light box during the preparation of an agarose electrophoresis gel used in DNA separation

Agarose is a polysaccharide that is isolated and purified from agar or agar-bearing marine algae (sea kelp). Structurally, agarose is a natural polymer, consisting of alternating β-D-galactose and 3,6-anhydro-L-galactose units of agarobiose. The linear agarose polymer forms chains which create fibers that are flexible and form a web of channels with diameters from 50 nm to 200 nm, depending on the amount of agarose used. Agarose is non-toxic and has several variable properties which make it useful as a gelling agent in many applications, such as nucleic acid electrophoresis, immunodiffusion techniques, gel plates or overlays for cells in tissue culture, cell culture media, gel chromatography, affinity chromatography, and ion exchange chromatography. Agarose gel electrophoresis is a common life science laboratory technique to separate biological molecules based on their size, for example in the separation of DNA molecules.



Key agarose properties

Sulfate content: Used as an indicator of purity, since sulfate is the major ionic group present.

Gel strength: The force that must be applied to a gel to cause it to fracture.

Gel point: The temperature at which an aqueous agarose solution forms a gel as it cools. Agarose solutions exhibit hysteresis in the liquid-to-gel transition. Their gel point is not the same as their melting temperature.

Electroendosmosis (EEO): The movement of liquid through the gel varies. Anionic groups in an agarose gel are affixed to the matrix and cannot move, but dissociable counter cations can migrate toward the cathode in the matrix, giving rise to EEO. Since electrophoretic movement of biopolymers is usually toward the anode, EEO can disrupt separations because of internal convection.

We provide a wide array of agarose products with varying gel strengths, melting temperatures, gelling temperatures, and electroendosmosis (EEO) levels to accommodate all of your research applications. We maintain reliable agarose sources and continue to develop new agarose production capabilities to provide our customers with an uncompromising standard of quality and consistency. Come to the experts: We are scientists helping scientists.




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