Soft X – ray analysis 10 days after in vivo electroporation. Soft X-ray images of target muscles on day 10 after gene transfer with pCAGGS and pCAGGS-BMP-2, pCAGGS and pCAGGS-BMP-7, or pCAGGS-BMP-2 and pCAGGS-BMP-7. Radio-opaque areas were seen after electroporation with pCAGGS and pCAGGS-BMP-2 (arrow) or pCAGGS-BMP-2 and pCAGGS-BMP-7 (arrow). No opacities with well-defined margins were detected in muscles that received pCAGGS and pCAGGS-BMP-7 by electroporation. Scale bar: 10 mm.