Most high-resolution images of the microbial world require chemically altering the cell, thereby rendering it dead, or the use of special contrasting dyes to enhance the elements of interest. Now, scientists at the Department of Energy’s SLAC National Accelerator Laboratory have devised a technique to capture the first X-ray images of living bacteria.
The results from this study were released today in Nature Communications through an article entitled “Imaging single cells in a beam of live cyanobacteria with an X-ray laser” and represent a significant achievement and step toward visualizing complex biological processes, such as the molecular machinery of viral infections, photosynthesis, and cell division.
“We have developed a unique way to rapidly explore, sort, and analyze samples, with the possibility of reaching higher resolutions than other study methods,” said Janos Hajdu, Ph.D., professor of biophysics at Uppsala University in Sweden and coauthor on the study. “This could eventually be a complete game-changer.”
Scientists combined the SLAC Linac Coherent Light Source (LCLS) X-ray laser and cyanobacteria, blue-green alga, for their analysis technique. Specifically, the investigators sprayed live microbes in a narrow stream of humid gas through the LCLS X-ray pulses, which produced diffraction patterns that were picked up by an array of detectors.
While the current procedure provided detailed images of living cyanobacteria in a high-resolution 2D reconstruction, the SLAC team is confident that they will be able to produce 3D images in the near future, using the same technique.
Since this new method has the ability to capture almost 100 images per second, compiling millions of high-res X-ray images in a single day, it will combine the advantages of mass information capture with the challenges of data analysis. Ultimately, this technique will assist in merging biology with big data.
“You can study the full cycle of cellular processes, with each X-ray pulse providing a snapshot of the process you want to study,” said Tomas Ekeberg, Ph.D., biophysicist at Uppsala University and coauthor on the study.
Dr. Hajdu added, “One can start to analyze differences and similarities between groups of cellular structures and show how these structures interact: What is in the cell? How is it organized? Who is talking to whom?”
The LCLS researches are excited with the results they have obtained already, but say that they are working on achieving even greater resolution—down to fractions of a nanometer, possibly resolving molecules or even atoms.