Correlative all-optical quantification of mass density and mechanics of subcellular compartments with fluorescence specificity

eLife

Anna Taubenberger¹  Martin Nötzel¹  Gheorghe Cojoc¹  Raimund Schlüßler¹  Shovamaye Maharana²  Salvatore Girardo³  Paul Müller³  Timon Beck³  Shada Abuhattum³  Kyoohyun Kim³  Jochen Guck⁴  Simon Alberti⁵  Andreas Hermann⁶ 

[1] Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische Universität, Dresden, Germany;Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische Universität, Dresden, Germany;Department of Microbiology and Cell Biology, Indian Institute of Science, Bengaluru, India;Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische Universität, Dresden, Germany;Max Planck Institute for the Science of Light and Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany;Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische Universität, Dresden, Germany;Max Planck Institute for the Science of Light and Max-Planck-Zentrum für Physik und Medizin, Erlangen, Germany;Physics of Life, Technische Universität Dresden, Dresden, Germany;Biotechnology Center, Center for Molecular and Cellular Bioengineering, Technische Universität, Dresden, Germany;Physics of Life, Technische Universität Dresden, Dresden, Germany;Translational Neurodegeneration Section "Albrecht Kossel", University Rostock, and German Center for Neurodegenerative Diseases (DZNE), Rostock/Greifswald, Germany;

关键词: Brillouin microscopy;    optical diffraction tomography;    phase transition;    HeLa cells;    mechanical properties;    density measurement;    Human;   

DOI  :  10.7554/eLife.68490

来源: eLife Sciences Publications, Ltd

【 摘 要 】

Quantitative measurements of physical parameters become increasingly important for understanding biological processes. Brillouin microscopy (BM) has recently emerged as one technique providing the 3D distribution of viscoelastic properties inside biological samples − so far relying on the implicit assumption that refractive index (RI) and density can be neglected. Here, we present a novel method (FOB microscopy) combining BM with optical diffraction tomography and epifluorescence imaging for explicitly measuring the Brillouin shift, RI, and absolute density with specificity to fluorescently labeled structures. We show that neglecting the RI and density might lead to erroneous conclusions. Investigating the nucleoplasm of wild-type HeLa cells, we find that it has lower density but higher longitudinal modulus than the cytoplasm. Thus, the longitudinal modulus is not merely sensitive to the water content of the sample − a postulate vividly discussed in the field. We demonstrate the further utility of FOB on various biological systems including adipocytes and intracellular membraneless compartments. FOB microscopy can provide unexpected scientific discoveries and shed quantitative light on processes such as phase separation and transition inside living cells.

【 授权许可】

CC BY