Bead Loading to Introduce Nucleic Acids Into Adherent Cultured Cells: A Technique to Load Fluorescent Protein-Encoding Plasmids Into Adherent Mammalian Cells

Remove the medium from the cells, and gently aspirate all medium from around the edges of the chamber. Then, tilt the chamber at approximately a 45-degree angle, and remove the remaining drop of media in the central microwell. Pipette the bead loading solution gently onto the glass microwell present in the center of the chamber.

Use the bead loading apparatus to gently disperse a monolayer of glass beads on top of the cells. Ensure that the beads cover the cells completely. Pinch the chamber with two fingers. Lift it around two inches, and bring it down firmly using a force approximately equivalent to dropping the dish from that height.

Gently add the medium back into the chamber by pipetting slowly onto the plastic side of the chamber. Aspirate any floating beads without disturbing the cells. The entire bead loading procedure should be performed relatively quickly, so the cells do not dry out when they are without medium. Then, incubate the cells for 0.5 to 2 hours in the incubator.