A team of scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of Wisconsin-Milwaukee (UWM) announced that they have developed the first technique to offer full color infrared tomography. They say that they combined Fourier Transform Infrared (FTIR) spectroscopy with computed tomography (CT) scans to create a non-destructive 3D imaging technique that provides molecular-level chemical information with unprecedented detail of biological specimens with no need to stain or alter the specimen.

Researchers at Berkeley Lab and the University of Wisconsin- Milwaukee have reported the first full color infrared tomography. (Credit: Cait Youngquist)

Every type of molecule absorbs infrared (IR) light at specific wavelengths. IR spectroscopy can identify the chemical constituents of a sample and the application of the Fourier-transform algorithm allows all IR fingerprints to be simultaneously recorded. FTIR spectroscopy is especially valuable for imaging proteins and other biological samples because it is non-destructive and can be performed without altering the sample.

By combining FTIR with computed tomography, the researchers created the technique for reconstructing 3D images out of multiple cross-sectional slices, to achieve what is believed to be the first demonstration of FTIR spectro-microtomography. This technology involves low-energy IR photons that do not affect living systems and do not require artificial labels, contrast agents, or sectioning. It can provide a wealth of information for advanced spectral segregation techniques such as clustering, neural networks, and principal-component analysis.

The Berkeley Lab and UWM researchers have already successfully applied FTIR spectro-microtomography to obtain 3D images of the molecular architecture of plant cell walls and applied FTIR spectro-microtomography to study human hair, and an intact grouping of pluripotent mouse stem cells.