Polyethyleneimine

[jwb]

Has anyone used polyethyleneimine-based transfection reagents, such as those offered by Polyplus Transfection? How do they compare with lipid-based stuff? I find very few user reviews for these on the web.

[morkfromork]

I used PEI transfection at a workshop once and it actually worked really well with very little toxicity (We primarily use lipofectamine 2000 in the lab and the cells usually don't look so happy) . And I think PEI is relatively cheap as well. I'd say go for it and try it out on your cells, you might find it to be a magic bullet!!!

[jwb]

Hi morkfromork,

Was the PEI you used a proprietary formula or PEI sold in bulk by companies? I need a magic bullet, that's why I'm looking for alternatives! I'm finding serious issues with more than one type of common transient transfection procedure, for the type of experiments I'm doing. Proprietary formulas such as the ones from Polyplus turn out as expensive as lipid-based reagents, if I have seen the prices right, but buying PEI in bulk and using it would definitely be cheaper, though I don't know how long I might have to spend optimizing things.

[morkfromork]

Hi jwb,
It was some time since I went on the course but I still have the handbook. The only information that it has is "Linear polythylenimine (PEI) (25 kDa) made up to 1mg/ml in H2O and pH-ed to 7.2 with HCl, filter sterilized and stored at -80C".

It says the PEI:DNA ratio needs to be optimized for each cell line (we used DNA:PEI = 1:3 for H1299 cells)

Unfortunately there was no catalog number given.

It sounds like something they bought as a dry powder from a company, since it was a training course I'm betting they used the cheapest stuff possible, but the experiment still worked quite nicely.

Hope this helps.

Have you thought about trying electroporation? Initially the equipment is expensive but once you have it you can do as many electroporations as you like.

[jwb]

Hi monkfromork,

Thank you for the info. Branched PEI seems easier to find than linear, and doesn't work as well as the linear variety. I have been having weird problems with electroporation, about which I posted another thread a couple of weeks ago!

[biochembug]

Polysciences.com has the complete range of PEI.

[breaded]

I have recently been experimenting with PEI (linear, won't state brand name) as an alternative to lipid based reagents. Overall, the PEI exhibited a lower transfection efficiency, but was much more cost affective. Because the PEI is harsher on the cells, I've found transfecting at a higher cell density is optimal. There are a few other things to optimize (such as PEI:DNA ratio) and complexing time, but I'm sure vary immensely on your cell type and reaction conditions.

[kiranmedepalli]

Hi,
I am trying to deliver quantum dots (nanoparticles) freely diffused into live cells. I tried simple incubated which led to endocytic pathway and the quantum dots are sequestered in the endocytic vesicles.
I read that coating the surface of the quantum dots with PEI would bypass the endocytotic pathway. I was wondering if anybody tried that before or have any inputs on how to do it?
thanks.

[giglio87]

I am trying to buy some linear polyethyleneimine powder.... can someone help? I know about Polysciences.com, anyone else?