Methods of protein concentration and collection in cell culture medium

Concentration and collection method of protein in cell culture medium click times: 208 Author: anonymous published in: 2010-03-28 23:43 reprint please indicate that it comes from dingxiangyuan ask: I want to use supernatant as ELISA, but the concentration of protein in supernatant is not enough, what method can I use to concentrate the protein Protein concentration technology is a common method in immunology Several commonly used concentration technologies are introduced 1 It is widely used in Zui to concentrate protein solution with dialysis bag Put the protein solution to be concentrated into the dialysis bag (no dialysis bag can be replaced by cellophane), ligate, and sprinkle the polymer (6000-12000) such as polyethylene glycol (carbon wax), polyvinyl pyrrole, alkanone or sucrose outside the dialysis bag The absorbent can also be mixed into 30% - 40% solution, and the dialysis bag containing protein solution can be put in After the water absorbent is used, it can be put into the oven for drying or natural drying, and it can still be reused 2 Freeze drying method is a better way to concentrate protein It not only makes the protein not easy to denature, but also keeps the inherent components in the protein It is in the frozen state of direct sublimation to remove water The specific method is to freeze the protein solution at low temperature, and then move it into the dryer (the dryer is equipped with desiccant, such as NaOH, CaCl2 and silica gel) Airtight, rapid evacuation, and maintain in the state of evacuation The dried powder containing protein can be obtained after several hours The dried protein is easy to store and can be used in any concentration Freeze dryer can also be used for freeze-drying 3 The protein solution is put into the dialysis bag and blown under the electric fan This method is simple, but slow, and the temperature should not be too high, Zui should not exceed 15 ℃ 4 Ultrafiltration membrane concentration this method is to use microporous cellulose membrane to filter out water by high pressure, and the protein remains on the membrane to achieve the purpose of concentration There are two ways to concentrate: one is to use cellulose acetate membrane into a high-pressure filter, and filter under constant agitation; the other is to put protein solution into a dialysis bag, which is built on the vent of the vacuum dryer, and vacuum suction, so that the liquid in the bag exudes 5, gel concentration method using smaller pore size gel, such as SephadexG25 or G50, gel directly added to protein solution According to the amount of water absorption of dry glue and the multiple of protein solution concentration, the amount of dry glue needed is weighed In the fridge, the gel particles absorb water and are removed by centrifugation 6 Concentrated glue concentration glue is a kind of organic polymer with polymer network structure, which has strong water absorption performance Each gram of dry glue can absorb 120 ml-150 ml water It can absorb low molecular weight substances, such as water, glucose, sucrose, inorganic salt, etc it is suitable for concentration of biomacromolecules with molecular weight over 10000 After concentration, the recovery of protein can reach 80% - 90% It is more convenient than concentrated glue It can be directly added to the concentrated solution It must be noted that the pH value of the concentrated solution should be greater than the isoelectric point of the concentrated substance, otherwise cation exchange will occur on the surface of the concentrated adhesive, which will affect the recovery rate of the concentrated substance