chloroquine to improve transfection - useful or superfluous? (Apr/13/2007 )

in a protocol for Ca2+-precipitation/transfection it is recommended to add 2h after transfection some chloroquine solution to inhibit lysosomal DNA; I think it should improve transfection; has any one experience with and w/o chloroquine? does it really help to improve transfection? isn´t it cytotoxic?

The toxicity for CQ is cell type-dependent. I have not used myself in conjunction with Ca/Pi. You may also try glycerol or DMSO osmotic shock. I would say that the overall injury effect will add up for each component and treatment.

CQ does little for most lipid, or PEI-based transfection reagents.

I usually do not use chloroquine in CaPO4 transfections, only with DEAE-dextran. It does make a difference but can be toxic. Don't leave it on your cells for more than 3 hours, so for CaPO4, add it 3 hours before you plan to harvest.. I also do a 2 min, 10% DMSO (in PBS) "shock" after the transfection and from my experience of accidently forgetting to do that step, it makes a BIG difference.

Yes, I do the DMSO shock after the 6 hour CaPO4 incubation.