Living cells are ready for their close-ups, thanks to a new imaging technique that needs no dyes or other chemicals, yet renders high-resolution, three-dimensional, quantitative imagery of cells and their internal structures – all with conventional microscopes and white light. Called white-light diffraction tomography (WDT), the imaging technique opens a window into the life of a cell without disturbing it and could allow cellular biologists unprecedented insight into cellular processes, drug effects and stem cell differentiation.
The team of University of Illinois researchers, led by electrical and computer engineering and bioengineering professor Gabriel Popescu, published their results in the journal Nature Photonics.
“One main focus of imaging cells is trying to understand how they function, or how they respond to treatments, for example, during cancer therapies,” Popescu said. “If you need to add dyes or contrast agents to study them, this preparation affects the cells’ function itself. It interferes with your study. With our technique, we can see processes as they happen and we don’t obstruct their normal behavior.”
Because it uses white light, WDT can observe cells in their natural state without exposing them to chemicals, ultraviolet radiation, or mechanical forces – the three main methods used in other microscopy techniques. White light also contains a broad spectrum of wavelengths, thus bypassing the interference issues inherent in laser light – speckles, for example. Via 3-D imaging provides window into living cells, no dye required.