Optical Projection Tomography
The Cell-CT uses a technique called Optical Projection Tomography to render cells in 3D. This process is illustrated for a squamous cancer cell in the video below where a cell is shown transported through the Cell-CT’s glass micro-capillary by applying pressure to a gel that embeds cells. As the capillary spins, the cell is scanned from multiple perspectives yielding a set of pseudo-projection images. These images are combined together using a method known as Filtered Back-Projection, producing the final 3D cell volume.
Color and opacity may be adjusted in the reconstruction to emphasize aspects of the cell that are of interest. This process is shown for a ciliated columnar cell.
The cell is shown in maximum intensity projection. In the center and right panels, color and opacity have been adjusted to render the cytoplasm in translucent white, the nucleus in opaque blue and the interior of the nucleus in a green to red chromatic gradient with the nucleoli rendered in opaque red. The cell is shown whole at left and center and cropped at right. Individual cillia are approximately 0.2 microns in diameter. Observation of individual cilia in the video indicates that Cell-CT resolution is at least one-half micron.