"polyethylenimine" - 1 õppematerjal

Molekulaar- ja rakubioloogia

Esimene päev – rakkude transfekteerimine PEI (polyethyleneimines)-ga Attachment promoter Polyethyleneimines are used in the cell culture of weakly anchoring cells to increase attachment. PEI is a cationic polymer; the negatively charged outer surfaces of cells are attracted to dishes coated in PEI, facilitating stronger attachments between the cells and the plate. However, polyethylenimine expresses some toxicity if excess is left in solution. Transfection reagent Poly(ethylenimine) was the second polymeric transfection agent discovered, after poly-l-lysine. PEI condenses DNA into positively charged particles, which bind to anionic cell surface residues and are brought into the cell via endocytosis. Once inside the cell protonation of the amines results in an influx of counter-ions and a lowering of the osmotic potential. Osmotic