Agar is a heterogeneous mixture of two classes of polysaccharide: agaropectin and agarose. Both of the polysaccharide classes has same galactose based backbone and agaropectin is heavily modified with acidic side groups, such as sulphate and pyruvate. Agarose has a characteristic of forming a heat-reversible gel in dilute aqueous solution that is hydrophilic and macro porous, and does not contain charged groups or other adsorption centers. Agarose is being used in Gel - electrophoresis of DNA and Affinity chromatography. Agarose is used to determine the presence and distinguish the type of nucleic acids obtained after extraction and to analyze restriction digestion products.
The gel strength of each agarose is different. It is 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 - that is, their gel point is not the same as their melting temperature. Electroendosmosis (EEO) - in electrophoresis refers to the flow of water under the influence of an electric field due to immobilized charge groups on the matrix, primarily sulphate and carboxyl groups. 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, causing a net flow water through osmosis in that direction. Since electrophoretic movement of biopolymers is usually toward the anode, EEO can disrupt separations because of internal convection.
Titan Media has different types of agarose, for eg. Agarose, (High EEO), Agarose, High EEO (0.23 - 0.26), Agarose, Low EEO, Agarose Spl. (Low EEO), Agarose (Low melting Temp. 65°C) (Low Protoplast Culture), Agarose, Low EEO (0.5 - 0.13), Agarose, Medium EEO (0.16 - 0.19).