Which QIAGEN kit do you recommend for purifying plasmid DNA suitable for transfection of sensitive cells?

We recommend our EndoFree Plasmid Kits to isolate plasmid DNA suitable for transfecting sensitive cells and primary cells. The Endofree Plasmid kits are designed to remove endotoxins (i.e. lipopolysaccharides that are part of the bacterial cell wall) and are generally advantageous in providing higher transfection efficiencies.