title: High resolution 3D imaging of living cells with sub-optical wavelength phonons.
abstract: Label-free imaging of living cells below the optical diffraction limit poses great challenges for optical microscopy. Biologically relevant structural information remains below the Rayleigh limit and beyond the reach of conventional microscopes. Super-resolution techniques are typically based on the non-linear and stochastic response of fluorescent labels which can be toxic and interfere with cell function. In this paper we present, for the first time, imaging of live cells using sub-optical wavelength phonons. The axial imaging resolution of our system is determined by the acoustic wavelength (λa= λprobe/2n) and not on the NA of the optics allowing sub-optical wavelength acoustic sectioning of samples using the time of flight. The transverse resolution is currently limited to the optical spot size. The contrast mechanism is significantly determined by the mechanical properties of the cells and requires no additional contrast agent, stain or label to image the cell structure. The ability to breach the optical diffraction limit to image living cells acoustically promises to bring a new suite of imaging technologies to bear in answering exigent questions in cell biology and biomedicine.
authors.affiliation: Optics and photonics group, Faculty of Engineering, University of Nottingham,University Park, Nottingham, UK.
authors.forename: Fernando
authors.initials: F
authors.lastname: Pérez-Cota
authors.affiliation: Optics and photonics group, Faculty of Engineering, University of Nottingham,University Park, Nottingham, UK.
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Smith
authors.affiliation: Optics and photonics group, Faculty of Engineering, University of Nottingham,University Park, Nottingham, UK.
authors.forename: Emilia
authors.initials: E
authors.lastname: Moradi
authors.affiliation: Optics and photonics group, Faculty of Engineering, University of Nottingham,University Park, Nottingham, UK.
authors.forename: Leonel
authors.initials: L
authors.lastname: Marques
authors.affiliation: Optics and photonics group, Faculty of Engineering, University of Nottingham,University Park, Nottingham, UK.
authors.forename: Kevin F
authors.initials: KF
authors.lastname: Webb
authors.affiliation: Optics and photonics group, Faculty of Engineering, University of Nottingham,University Park, Nottingham, UK.
authors.forename: Matt
authors.initials: M
authors.lastname: Clark
mesh_terms: D016475:3T3 Cells; D000818:Animals; D002460:Cell Line; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D051379:Mice; D008853:Microscopy / Q000379:methods*; D033401:Microscopy, Acoustic / Q000379:methods*; D060739:Phonons; D059010:Single-Cell Analysis / Q000295:instrumentation / Q000379:methods*