Polycation-mediated transfection: how to overcome undesirable side effects of sticky DNA complexes

Using polycationic transfection one encounters undesired persistent binding to cells of sticky polycation/DNA complexes. These complexes simulate transfection under conditions where no uptake is expected e.g. at 4 degrees C if the uptake is by endocytosis. To overcome this problem, using H1/DNA complexes, we developed an easy and nontoxic method for removing the sticky complexes not taken up during the transfection phase. The cells are simply washed with isotonic (0.1 M) MgCl2 solution, which enables the complete removal of the complexes by their rapid dissolution.