Quentin Fallavier, France) in anhydrous form.
Souffleweyersheim, France). Both preparations should be stored at 4°C having adjusted the pH to ≤4.0.
The stock solution (0.1 M) of PEI provided by Euromedex (22 kDa) is used as supplied. The 25 kDa obtained is prepared as follows: weigh 4.5 mg of the solution, mix with 800 μL of sterile water thus obtaining a 0.1 M solution. Adjust the pH to ≤4.0 with 0.1 N HCl and the volume to 1 mL. Solutions are kept as aliquots at 4°C or at -20°C for long term storage (>1 month).