sephadex-LH20（sephadex -LH20）.doc

sephadex-LH20（sephadex -LH20） 1 Sephadex LH20 is a high price filler, please pay attention, very expensive yo! (of course, the boss has the money.) Lets start with the principle of Sephadex LH20. The separation principle of Sephadex LH20 is mainly in two aspects: it is mainly based on the gel filtration, and it has the effect of anti-phase distribution (in the anti-phase solvent). Because of the gel filtration, the compound of the macromolecules remains weak, first eluting, the small molecules of the compound retained strong, and finally the column. If using reverse phase solvent elution and Sephadex LH20 inverse distribution effect to the compound, so weak polar compounds retained, had been down first polar compounds retain strong, after the column. If you are using a positive phase solvent, this is mainly separated by gelling. 3. Sephadex LH20 elution solvent. After listening to the second point, it should be clear that the Sephadex LH20 elution solvent is divided into two types: reverse and positive. The most used is the anti-phase solvent eluting, with methanol - water system is the most common, first water, gradually increase the proportion of methanol, and finally use 100 % methanol shock column. The positive phase system is chloroform - methanol is the most common, with 50% chloroform - methanol, gradually increasing the proportion of methanol, and finally using 100% methanol shock column. Next, we will discuss the sample processing and the choice of solvent cleaning. If the sample polarity is big, the selection of reverse phase solvent elution (methanol, water), the sample with a minimum volume of methanol - water (methanol less as far as possible) dissolved, after filtration, wet on the sample (must filter oh! If the Sephadex LH20 plugging, will have to Sephadex LH20 stigma of abandon, very heartache ah). If the sample polarity is small, this is a positive solvent eluting (chloroform - methanol), the sample with a minimum volume of chloroform - methanol di