Merck, A2929-25G, Agarose

Application
Especially formulated for fast resolution of large DNA (10-2000 ·kb) by pulsed-field gel electrophoresis (PFGE) or conventional electrophoresis. Pulsed-field gel electrophoresis was developed in 1984 to deal with "reptation" of large DNA′s whose size surpass the limit of resolution and all migrate at the same rate. Alternately pulsed, orthogonally oriented electric fields are applied across the gel. Every time the direction of the electric field changes, the large DNA′s can no longer migrate until they become reoriented along the new electric field. The time required for reorientation is dependent on the size of the DNA, therefore the DNA is fractionated by size.
Biochem/physiol Actions
Suitable for the separation of high molecular weight DNA. Gels are easy to handle and give faster separation and better resolution of high molecular weight DNA by field inversion electrophoresis than our routine-use agarose.
Features and Benefits

• Low EEO allows for increased voltages and more rapid DNA migration
• Greater gel strength allows for stability of lower concentration gels leading to faster DNA migration
• Gels exhibit low background fluorescence using ethidium bromide staining

Analysis Note
The following is a list of properties associated with our agaroses:
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 - that is, their gel point is not the same as their melting temperature.
Electroendosmosis (EEO) - a movement of liquid through the gel. 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.