生化实验（Biochemical experiment）.docVIP

生化实验（Biochemical experiment） Separation of serum proteins -- DEAE cellulose ion exchange chromatography Ion-exchange chromatography: Definition: stationary phase is a chromatographic technique for ion exchangers. That is to be separated in a sample of solute ions, ion and stationary phase with the combination of the exchange, the solute ions and ion exchange agent on different ionizable group affinity and binding conditions are different, when the mobile phase flows, ion in the sample according to the binding force were successively eluted. Composition: stationary phase ion exchanger Mobile phase - an electrolyte solution with a certain pH value and a certain ionic strength Chromatography: is the use of physical and chemical properties of each component in the mixture differences such as solubility, adsorption ability, molecular shape and size, molecular polarity, the components in the distribution of two different phases, and the components can be different with the flow velocity to achieve separation before moving to. Purification of serum gamma globulin The principle of protein salting out: Two stabilizing factors of protein colloid solution (1) charge Cause them to repel each other and not agglomerate easily (2) hydration film The colloidal particles are combined with water and act as an isolating agent between the colloidal particles Salting out principle: the two stabilizing factor (charge, hydration film) that destroys proteins, which precipitates proteins 1, attract water molecules, seize the hydration film 2, neutralization and partial charge Common salts of protein salting out: Ammonium sulphate, sodium sulphate, sodium chloride, Magnesium Sulfate Advantages of ammonium sulfate: 1, solubility It can reach 541 g / L at 25 4.1M 2, the temperature coefficient is small Solubility is not affected by temperature 3, it is difficult to cause protein denaturation 4, the price is low Disadvantages of ammonium sulfate: Containing ammonium ions can interfere with biur