Figure 5
From: Use of inert gas jets to measure the forces required for mechanical gene transfection
Pore size and duration during permeabilization. (A) Time course study. The 40 kDa dextran solution was added before treatment, 1 second after treatment or 5 seconds after treatment. Dextran molecules are membrane impermeant. Fluorescent cells indicate that the membrane of the cell was permeabilized at the time the solution was added. (B) Size exclusion study. Dextran molecules of 3 kDa, 10 kDa (1.9 nm hydrodynamic radius), 40 kDa (4.8 nm hydrodynamic radius) and 70 kDa (6.5 nm hydrodynamic radius) were added to the media before treatment. Cells were treated with helium gas, using a capillary diameter of 0.68 mm and a flow rate of 1.3 L/min for all dextrins (297 Pa). No fluorescence could be detected using 70 kDa dextran molecules. Fluorescent cells indicate that the membrane of the cell was permeabilized. Scale bar (A,B) 200 μm.