Introduction to agarose gel
Based on the principle of gel filtration chromatography, the most basic requirement for its medium is that it cannot have any other interaction with the raw material components except for exclusion, such as charge effect, chemical effect, biological effect, etc. The ideal gel filtration medium has high physical strength and chemical stability, can withstand high temperature and high pressure and strong acid and alkali, has high chemical inertness, narrow inner pore size distribution, and bead-like particle size uniformity. Currently commonly used are sepharose, agarose gel, polyacrylamide gel and so on.
Agarose gel is derived from a kind of seaweed polysaccharide agar, which is a natural gel, not covalently cross-linked, so the bond energy of hydrogen bond cross-linking is relatively weak. Unlike dextran, porosity is achieved by varying the agarose concentration. The chemical stability of agarose gel is not as good as that of sepharose. Agarose gel has no dry gel and must be stored in a swollen state. Except for acetone and ethanol, agarose gel will be destroyed when it encounters dehydrating agents, freezing agents and some organic solvents. The suitable working conditions for separation operation with agarose gel are pH4.5-9 and temperature 0-40℃. Agarose gel has adsorption effect on borate, so boric acid buffer cannot be used.
Agarose gel particles are very weak and must be handled with great care. In addition, due to the small elasticity of agarose particles, the pressure caused by the height of the column can lead to deformation, resulting in reduced flow rate or even blockage, so try to adjust the column pressure when packing the column. Agarose gel has no charged groups, so the non-specific adsorption force for protein substances is significantly smaller than that of sepharose. There is no obvious adsorption when the ion concentration of the medium is greater than 0.1mol/L.
The characteristic of agarose gel is that it can separate tens of thousands to tens of millions of high molecular weight substances. The separation range decreases with the increase of the gel concentration, but the particle strength increases with the increase of the concentration. It is especially suitable for nucleic acids, polysaccharides and The separation of protein substances makes up for the deficiencies of polyacrylamide gel and dextran gel and expands the application range.
The name of Welch Materials agarose gel is Tanrose. The following introduces Tanrose Fast Flow series products.
Tanrose Fast Flow Series
Tanrose 4FF and Tanrose 6FF are gel filtration media obtained by emulsification, rinsing and sieving of 4% and 6% agarose respectively. The media has good physical and chemical stability. The media can be quenched with sodium hydroxide. bacteria can also be autoclaved. It is used for the separation, purification or detection of polysaccharides, nucleic acids, viruses, supercoiled DNA and macromolecular complexes.