Agarose is generally heated to above 90℃ and dissolved in water. When the temperature drops to 35-40℃, it forms a good semi-solid gel, which is the main feature and foundation of its various uses. The performance of agarose gel is usually expressed by gel strength. The higher the strength, the better the gel performance. The strength of high-quality agarose is usually above 1200g /cm2 (1% gel concentration). The gelation of agarose is due to the existence of hydrogen bonds, and all factors that can destroy hydrogen bonds will lead to the destruction of gelation. Agarose is hydrophilic, almost contains no charged groups, and rarely causes denaturation and adsorption to sensitive biological macromolecules, so it is an ideal inert carrier. During the preparation of agarose, it is necessary to remove pectin from the agar as much as possible, otherwise a very small amount of sulfate and pyruvic acid may replace the ionized groups in the agarose, causing electroosmosis (EEO), thus affecting the movement of particles. The sulfate content of good quality agarose is relatively low, generally below 0.2%, and the electroosmosis is relatively small, generally below 0. 13. This is why agarose is much more expensive than agar.
Agarose was first isolated from agar in 1937, but it was not until 196 1 Hjertin first discovered the excellent performance of agarose that it attracted more and more attention and started industrial production. Agarose is widely used in clinical laboratory, biochemical analysis and separation of biological macromolecules.