title: Nanometer-scale imaging by the modulation tracking method.
abstract: We developed an optical imaging method based on a feedback principle in which the specific scan pattern is adapted according to the shape of the sample. The feedback approach produces nanometer-resolved 3D images of very small and moving features in live cells in seconds. We show images of microvilli in live cultured opossum kidney cells expressing NaPi co-transporter proteins with different GFP constructs and images of cell protrusions in a collagen matrix with a resolution of about 20 nm. We found that in the microvilli the NaPi proteins can be found clustered. Along cell protrusions in 3D we identified cellular adhesions to the extracellular matrix. Our approach to super-resolution and to 3D nanoimaging is different than other proposed methods that break the diffraction limit using non-linear effects or are based on single molecule localization.
authors.affiliation: Laboratory for Fluorescence Dynamics, University of California - Biomedical Engineering, 3210 Natural Sciences 2, Irvine, California 92672, USA.
authors.forename: Luca
authors.initials: L
authors.lastname: Lanzano
authors.forename: Michelle A
authors.initials: MA
authors.lastname: Digman
authors.forename: Peter
authors.initials: P
authors.lastname: Fwu
authors.forename: Hector
authors.initials: H
authors.lastname: Giral
authors.forename: Moshe
authors.initials: M
authors.lastname: Levi
authors.forename: Enrico
authors.initials: E
authors.lastname: Gratton
mesh_terms: D000465:Algorithms; D000818:Animals; D002448:Cell Adhesion; D003952:Diagnostic Imaging / Q000379:methods*; D005109:Extracellular Matrix / Q000378:metabolism; D049452:Green Fluorescent Proteins / Q000737:chemistry / Q000378:metabolism; D021621:Imaging, Three-Dimensional / Q000379:methods*; D007368:Interferometry / Q000379:methods; D007668:Kidney / Q000378:metabolism; D008840:Microfilament Proteins / Q000378:metabolism; D008856:Microscopy, Fluorescence / Q000379:methods*; D036103:Nanotechnology / Q000379:methods*; D009893:Opossums; D055095:Optics and Photonics
chemical_list: D008840:Microfilament Proteins; C042653:microvillin; D049452:Green Fluorescent Proteins