Do you use a home-made PEI?

We store it in aliquots at -20C. The vial in use is kept at 4C and works fine for a long time,

Here is our protocol how to make it:

PEI (1ug/ul) – PEI is Polyethylenimine 25kD linear from Polysciences (cat# 23966-2).

To make a stock solution:

• Dissolve PEI in endotoxin-free dH2O that has been heated to ~80°C.

• Let cool to room temperature.

• Neutralize to pH 7.0, filter sterilize (0.22um), aliquot and store at -20°C; a working stock can be kept at 4°C.

Best wishes

A

Do you use a home-made PEI?

We store it in aliquots at -20C. The vial in use is kept at 4C and works fine for a long time,

Here is our protocol how to make it:

PEI (1ug/ul) – PEI is Polyethylenimine 25kD linear from Polysciences (cat# 23966-2).

To make a stock solution:

• Dissolve PEI in endotoxin-free dH2O that has been heated to ~80°C.

• Let cool to room temperature.

• Neutralize to pH 7.0, filter sterilize (0.22um), aliquot and store at -20°C; a working stock can be kept at 4°C.

Best wishes

A

Thanks Adolfo, I miss you so much. When Nafis come here in Apirl he said you are travelling for your vacation. The PEI we bought from polysciences cat# 24765-2 it's fully hyddrolyzed linear polyethylenimine. And we prepare for transfection in vivo, it's okay when we test in cell line transfection at first time adherent your protocol described above. After that our in vivo transfection result was confuesd, now we focus on two things one is purity and content of pasmid DNA, the other one is PEI stock solution lost it's function.

For in vivo we have tried, unsuccessfully our own mix, but the commercial one (in vivo jet pei) worked "OK" in testes.

We tried a few different concentration ranges from our own PEI but no good results. May be lower pH does help, and a freeze/thawing cycle too (thanks to Laetitia for the tip!) we did not go that far and instead ordered the commercial one :-)

Best regards to all the friends in Beijing!

Thanks Laetitia and Adolf for your help, recently I try my home made PEI again and it indeed can transfection Lung but efficiency is very low. Laetitia can you give me some literature about the frozen and thawed method used in transfection. I can't find out any paper infer this method.