Imaging Cells in Liquid with a Near-Field Scanning Optical Microscope - Problems and Solutions

1999 ◽  
Vol 5 (S2) ◽  
pp. 390-391
Author(s):  
Levi A. Gheber ◽  
Michael Edidin

Near Field Scanning Optical Microscopy (NSOM) is the newest member of the Scanning Probe Microscopy (SPM) family, which includes Scanning Tunneling Microscopy (STM) and Atomic Force Microscopy (AFM). Like its predecessors, it uses a sharp tip and a very precise positioning system to scan the surface of samples. The important difference is that the NSOM tip is made of an optical fiber, with a sub-wavelength size aperture at its end, which is brought to near-field proximity to the sample. In the near-field regime, the resolution is only limited by the size of the light source (the aperture), and not by the wavelength of light, thus allowing NSOM to obtain images with subwavelength resolution. Applying NSOM to biological samples is very appealing, since biological research has developed a wide variety of fluorescent dyes which can be directed with high specificity to objects of interest. Moreover, biological research relies to a large extent on conventional fluorescence microscopy, which is diffraction limited. Application of NSOM to biological problems requires the ability to image rough and soft samples in liquid, a task that presents many challenges.We have developed a NSOM which is capable of imaging cells in liquid with a resolution of ∼150 nm. This has enabled us to image the organization of fluorescently labeled proteins on the membrane of cells in liquid, and demonstrate for the first time that the proteins are clustered.

Author(s):  
E. Betzig ◽  
M. Isaacson ◽  
H. Barshatzky ◽  
K. Lin ◽  
A. Lewis

The concept of near field scanning optical microscopy was first described more than thirty years ago1 almost two decades before the validity of the technique was verified experimentally for electromagnetic radiation of 3cm wavelength.2 The extension of the method to the visible region of the spectrum took another decade since it required the development of micropositioning and aperture fabrication on a scale five orders of magnitude smaller than that used for the microwave experiments. Since initial reports on near field optical imaging8-6, there has been a growing effort by ourselves6 and other groups7 to extend the technology and develop the near field scanning optical microscope (NSOM) into a useful tool to complement conventional (i.e., far field) scanning optical microscopy (SOM), scanning electron microscopy (SEM) and scanning tunneling microscopy. In the context of this symposium on “Microscopy Without Lenses”, NSOM can be thought of as an addition to the exploding field of scanned tip microscopy although we did not originally conceive it as such.


Author(s):  
E. Betzig ◽  
A. Harootunian ◽  
M. Isaacson ◽  
A. Lewis

In general, conventional methods of optical imaging are limited in spatial resolution by either the wavelength of the radiation used or by the aberrations of the optical elements. This is true whether one uses a scanning probe or a fixed beam method. The reason for the wavelength limit of resolution is due to the far field methods of producing or detecting the radiation. If one resorts to restricting our probes to the near field optical region, then the possibility exists of obtaining spatial resolutions more than an order of magnitude smaller than the optical wavelength of the radiation used. In this paper, we will describe the principles underlying such "near field" imaging and present some preliminary results from a near field scanning optical microscope (NS0M) that uses visible radiation and is capable of resolutions comparable to an SEM. The advantage of such a technique is the possibility of completely nondestructive imaging in air at spatial resolutions of about 50nm.


Open Physics ◽  
2010 ◽  
Vol 8 (3) ◽  
Author(s):  
Petr Klapetek ◽  
Juraj Bujdák ◽  
Jiří Buršík

AbstractThis article presents results of near-field scanning optical microscope measurement of local luminescence of rhodamine 3B intercalated in montmorillonite samples. We focus on how local topography affects both the excitation and luminescence signals and resulting optical artifacts. The Finite Difference in Time Domain method (FDTD) is used to model the electromagnetic field distribution of the full tip-sample geometry including far-field radiation. Even complex problems like localized luminescence can be simulated computationally using FDTD and these simulations can be used to separate the luminescence signal from topographic artifacts.


1997 ◽  
Vol 474 ◽  
Author(s):  
E. B. McDaniel ◽  
J. W. P. Hsu

ABSTRACTWe incorporate a polarization modulation technique in a near-field scanning optical microscope (NSOM) for quantitative polarimetry studies at the nanometer scale. Using this technique, we map out stress-induced birefringence associated with submicron defects at the fusion boundaries of SiTiO3 bicrystals. The strain fields surrounding these defects are larger than the defect sizes and show complex spiral shapes that break the reflection symmetry of the bicrystal boundary.


1993 ◽  
Vol 1 (8) ◽  
pp. 2-3 ◽  
Author(s):  
Jean-Paul Revel

As the year ends there is a bumper crop of announcements of advances that I find absolutely amazing. First of course is the continued clever use of light as a veritable tool in manipulating everything from atoms (entrapping them in “atomic molasses”) to having tugs of war with biological motors (using “light tweezers”). But these developments will be for discussion another time. What I want to talk about in this installment are advances in Near Field Scanning Optical Microscopy (NSOM), which has now been used by Chichester and Betzig to visualize single molecules.In classical (far field) optics, resolution is limited by diffraction to about 1/2 the wavelength of the radiation used for imaging. Near field optics overcome this limitation by use of scanning techniques similar to those employed in Scanning Tunneling or Scanning Force Microscopy.


Author(s):  
Yuan Wang ◽  
Cheng Sun ◽  
Nicholas Fang ◽  
Xiang Zhang

Recently, near-field scanning optical microscopy (NSOM) and its variations, which combine the scanning probe technology with optical microscopy, have been intensively applied in the study of biology, material science, surface chemistry, information storage, and nanofabrication. However, due to the serial scanning nature, the speed at which NSOM can successively records highly resolved images is rather limited. This hampers the applications of NSOM in characterizing dynamic response of particular samples. In this article, we perform systematic investigation of NSOM system parameters, which include scan rate, signal detector amplification, and illumination intensity. In this work, a model of signal flow for the NSOM system has been established to quantitatively investigate the interplay of the key process parameters and to further explore the technique solutions for high-speed NSOM imaging. The model is in good agreement with experimental results and the optimized conditions for high speed NSOM imaging are suggested.


1995 ◽  
Vol 406 ◽  
Author(s):  
A. H. La Rosa ◽  
B. I. Yakobson ◽  
H. D. Hallen

AbstractA contactless high spatial resolution technique has been developed to characterize semiconductor materials using the Near-Field Scanning Optical Microscope. The technique can be used to non-invasively measure: surface topography, defect content, and carrier lifetime variations in silicon. The success of the technique relies on the sensitive detection of changes in infrared transmission induced by local generation of free carriers using pulsed visible radiation. Here we extend the application of this technique to characterize silicon on insulator materials. We also include computer simulation results to address the role played by diffusion in the ultimate lateral resolution that can be achieved using this technique.


2014 ◽  
Vol 595 ◽  
pp. 56-60
Author(s):  
Yuji Sekido ◽  
Kozo Taguchi

Generally, the metal probe for NSOM (Near field scanning optical microscopy) or STM (Scanning Tunneling Microscope) was made with gold or tungsten. However, they were not suitable for the cell trap in our research for the reasons of cost, hardness, etc. In our research, these problems were solved by choosing brass as a material of a probe. Since the probe production by electrolytic polishing can change the shape of the top, tip angle, and taper length etc, we can propose a probe suitable for a cell trap. Therefore, in this examination, we propose the brass probe by electrolytic polishing with low cost and sufficient hardness for cell trap.


1994 ◽  
Vol 2 (2) ◽  
pp. 4-4
Author(s):  
Gary Aden

Prior to Near-Field Scanning Optical Microscopy (NSOM) there were two major light microscopy techniques; optical and confocal.In an optical microscope a sample is illuminated with a flood of light. The lighted area is then imaged and magnified by collecting the light that is either reflected from or transmitted through the sample by a series of glass lenses. A color magnified image of the sample may be seen directly or displayed on a TV screen. Even if the lenses could be made perfectly, the resolution and magnification of an optical microscope are limited by diffraction effects to approximately one half of the wavelength of the light that is used. Optical microscopes are used routinely to image the general shape of samples as small as human chromosomes or compact disk bits.


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