Stain‐free 3D Nanoscopy of Living Cells

Abstract

Abstract The cell is the basis of all life on earth. Therefore, being capable of directly observing and measuring the internal parts of a living cell would open a wealth of possibilities. However, due to the limitation of light used as a biological probe, revealing this internal structure is either strongly limited or requires strong and tedious modifications of observed cells. State‐of‐the art microscopy techniques rely on complicated procedures (risk of errors), which require difficult and time‐consuming preparations, are invasive to the cells (risk of damaging and results falsification), and still give rather limited results. This article presents a novel non‐invasive and tomographic imaging approach for quantitative analysis and differentiation of cell components. Changes in refractive index within the cell itself provide the contrast for labeling various organelles with high precision and at a high resolution. The method can be applied to the 3D examination of living cells and biological samples under various external stimuli or drugs.