DuPont on X-Ray Tomography

Genetic modifications in plants can lead to structural modifications within a plants seeds. DuPont has been investigating changed in arabidopsis seeds since its genetic code is completely known. Wild type seeds with no genetic alterations are compared with seeds that have genetic alterations made. A three dimensional movie of three arabidopsis seeds mounted on a glass fiber is available for download. Download animation (2.2MB AVI)

Visualization of AFM Images of Nanoscale DNA Templates
Used in Nanodevice Fabrication

The two pictures on this page are visualizations of the same Atomic Force Microscope (AFM) image done in different ways with VTK. The pictures show two short strands of DNA stretched across the gap between a pair of gold electrodes.The two strands of DNA are visible at the bottom the trench between the electrodes. Proteins can be synthesized that will bind to specific unique locations in the DNA template. The resulting DNA template structure enables researchers to assemble the components for a nanoscale device in the precise order or location needed. The DNA strands in the images are only1 nanometer tall and the seemingly enormous trench is only 400nm wide. By comparison, a human hair is 40,000 nm wide.

VTK has several valuable features which make it ideal for visualization of the 512x512 "range" images produced by AFM's. The availability of spot lights in VTK has been essential for displaying fine surface detail in AFM images. The use of 2 spotlights to make the 1 nm tall strands of DNA stand out may not be readily apparent when gold spotlights are used but is easy to see with the orange spot lights. The ability to make arbitrarily large image files with vtkRenderLarge makes it extremely easy to generate images for publication. For example, the images on this page were originally 2400x2400 resolution before downsizing. Some of the other useful features of VTK for AFM image visualization are available in the object classes vtkImageGaussian for smoothing, vtkImageWarp to create a polygonal surface from an image and several object classes for polygonal surface decimation.

Links:
http://www.cnf.cornell.edu/2002cnfra/2002cnfra.html http://www.cnf.cornell.edu/2002cnfra/2002cnfra126.pdf