Figure 2

Nano and micro-particles show similar efficiency when transfected into HEK 293 cells. A and B. Cells were transfected with a single 'shot' containing 0.5, 1 or 2 μg of DNA encoding yellow fluorescent protein (YFP) precipitated onto gold projectiles. The cells were incubated for 24 h, fixed, and then examined using a confocal microscope. For further details see text. Images are representative of > 1000 cells from at least 6 transfections. Cells transfected with uncoated gold particles or those with 0.25 μg DNA resulted in no expression (data not shown). YFP = yellow fluorescent protein; DAPI = diamidinophenylindole which reveals cell nuclei; MERGE = combined images. Scale bar = 15 μm. C. Typical low resolution images of HEK293 cells biolistically transfected with 1 μg of YFP-DNA using 1 μm or 40 nm gold projectiles. Scale bar = 100 μm.