scholarly journals Laser spectroscopic technique for direct identification of a single virus I: FASTER CARS

2020 ◽  
Vol 117 (45) ◽  
pp. 27820-27824 ◽  
Author(s):  
Volker Deckert ◽  
Tanja Deckert-Gaudig ◽  
Dana Cialla-May ◽  
Jürgen Popp ◽  
Roland Zell ◽  
...  
Keyword(s):  
Clinical Sample ◽  
H1n1 Influenza ◽  
Spectroscopic Technique ◽  
Spectroscopic Techniques ◽  
Force Microscopy ◽  
Virus Particles ◽  
Detection Techniques ◽  
Atomic Force ◽  
Enhanced Resolution ◽  
Anti Stokes

From the famous 1918 H1N1 influenza to the present COVID-19 pandemic, the need for improved viral detection techniques is all too apparent. The aim of the present paper is to show that identification of individual virus particles in clinical sample materials quickly and reliably is near at hand. First of all, our team has developed techniques for identification of virions based on a modular atomic force microscopy (AFM). Furthermore, femtosecond adaptive spectroscopic techniques with enhanced resolution via coherent anti-Stokes Raman scattering (FASTER CARS) using tip-enhanced techniques markedly improves the sensitivity [M. O. Scully,et al.,Proc. Natl. Acad. Sci. U.S.A.99, 10994–11001 (2002)].

scholarly journals Atomic Force Microscopy Investigation of Human Immunodeficiency Virus (HIV) and HIV-Infected Lymphocytes

2003 ◽  
Vol 77 (22) ◽  
pp. 11896-11909 ◽  
Author(s):  
Y. G. Kuznetsov ◽  
J. G. Victoria ◽  
W. E. Robinson ◽  
A. McPherson
Keyword(s):  
Human Immunodeficiency Virus ◽  
Atomic Force Microscopy ◽  
Nucleic Acid ◽  
Matrix Protein ◽  
Human Lymphocytes ◽  
Tween 20 ◽  
Force Microscopy ◽  
Virus Particles ◽  
Atomic Force ◽  
Immunodeficiency Virus

ABSTRACT Isolated human immunodeficiency virus (HIV) and HIV-infected human lymphocytes in culture have been imaged for the first time by atomic force microscopy (AFM). Purified virus particles spread on glass substrates are roughly spherical, reasonably uniform, though pleomorphic in appearance, and have diameters of about 120 nm. Similar particles are also seen on infected cell surfaces, but morphologies and sizes are considerably more varied, possibly a reflection of the budding process. The surfaces of HIV particles exhibit “tufts” of protein, presumably gp120, which do not physically resemble spikes. The protein tufts, which number about 100 per particle, have average diameters of about 200 Å, but with a large variance. They likely consist of arbitrary associations of small numbers of gp120 monomers on the surface. In examining several hundred virus particles, we found no evidence that the gp120 monomers form threefold symmetric trimers. Although >95% of HIV-infected H9 lymphocytic cells were producing HIV antigens by immunofluorescent assay, most lymphocytes displayed few or no virus on their surfaces, while others were almost covered by a hundred or more viruses, suggesting a dependence on cell cycle or physiology. HIV-infected cells treated with a viral protease inhibitor and their progeny viruses were also imaged by AFM and were indistinguishable from untreated virions. Isolated HIV virions were disrupted by exposure to mild neutral detergents (Tween 20 and CHAPS) at concentrations from 0.25 to 2.0%. Among the products observed were intact virions, the remnants of completely degraded virions, and partially disrupted particles that lacked sectors of surface proteins as well as virions that were split or broken open to reveal their empty interiors. Capsids containing nucleic acid were not seen, suggesting that the capsids were even more fragile than the envelope and were totally degraded and lost. From these images, a good estimate of the thickness of the envelope protein-membrane-matrix protein outer shell of the virion was obtained. Treatment with even low concentrations (<0.1%) of sodium dodecyl sulfate completely destroyed all virions but produced many interesting products, including aggregates of viral proteins with strands of nucleic acid.

scholarly journals The mechanisms underlying the enhanced resolution of atomic force microscopy with functionalized tips

2010 ◽  
Vol 12 (12) ◽  
pp. 125020 ◽  
Author(s):  
Nikolaj Moll ◽  
Leo Gross ◽  
Fabian Mohn ◽  
Alessandro Curioni ◽  
Gerhard Meyer
Keyword(s):  
Atomic Force Microscopy ◽  
Force Microscopy ◽  
Atomic Force ◽  
Enhanced Resolution ◽  
Functionalized Tips

scholarly journals Cylindrical inclusion protein of potato virus A is associated with a subpopulation of particles isolated from infected plants

2008 ◽  
Vol 89 (3) ◽  
pp. 829-838 ◽  
Author(s):  
Rasa Gabrenaite-Verkhovskaya ◽  
Igor A. Andreev ◽  
Natalia O. Kalinina ◽  
Lesley Torrance ◽  
Michael E. Taliansky ◽  
...  
Keyword(s):  
Potato Virus ◽  
Immunogold Labelling ◽  
Cylindrical Inclusion ◽  
Force Microscopy ◽  
Virus Particles ◽  
Potato Virus A ◽  
Atomic Force ◽  
Inclusion Protein ◽  
Cylindrical Inclusion Protein ◽  
Gradient Separation

Potato virus A (PVA) particles were purified by centrifugation through a 30 % sucrose cushion and the pellet (P1) was resuspended and sedimented through a 5–40 % sucrose gradient. The gradient separation resulted in two different virus particle populations: a virus fraction (F) that formed a band in the gradient and one that formed a pellet (P2) at the bottom of the gradient. All three preparations contained infectious particles that retained their integrity when visualized by electron microscopy (EM). Western blotting of the P1 particles revealed that the viral RNA helicase, cylindrical inclusion protein (CI), co-purified with virus particles. This result was confirmed with co-immunoprecipitation experiments. CI was detected in P2 particle preparations, whereas F particles were devoid of detectable amounts of CI. ATPase activity was detected in all three preparations with the greatest amount in P2. Results from immunogold-labelling EM experiments suggested that a fraction of the CI present in the preparations was localized to one end of the virion. Atomic force microscopy (AFM) studies showed that P1 and P2 contained intact particles, some of which had a protruding tip structure at one end, whilst F virions were less stable and mostly appeared as beaded structures under the conditions of AFM. The RNA of the particles in F was translated five to ten times more efficiently than RNA from P2 particles when these preparations were subjected to translation in wheat-germ extracts. The results are discussed in the context of a model for CI-mediated functions.

scholarly journals Nanoscale Wetting of Single Viruses

Molecules ◽  
2021 ◽  
Vol 26 (17) ◽  
pp. 5184
Author(s):  
Annalisa Calò ◽  
Aitziber Eleta-Lopez ◽  
Thierry Ondarçuhu ◽  
Albert Verdaguer ◽  
Alexander M. Bittner
Keyword(s):  
Relative Humidity ◽  
Viral Infections ◽  
High Sensitivity ◽  
Water Layer ◽  
Dynamic Force ◽  
Force Microscopy ◽  
Virus Particles ◽  
Ambient Relative Humidity ◽  
Atomic Force ◽  
Condensed Water

The epidemic spread of many viral infections is mediated by the environmental conditions and influenced by the ambient humidity. Single virus particles have been mainly visualized by atomic force microscopy (AFM) in liquid conditions, where the effect of the relative humidity on virus topography and surface cannot be systematically assessed. In this work, we employed multi-frequency AFM, simultaneously with standard topography imaging, to study the nanoscale wetting of individual Tobacco Mosaic virions (TMV) from ambient relative humidity to water condensation (RH > 100%). We recorded amplitude and phase vs. distance curves (APD curves) on top of single virions at various RH and converted them into force vs. distance curves. The high sensitivity of multifrequency AFM to visualize condensed water and sub-micrometer droplets, filling gaps between individual TMV particles at RH > 100%, is demonstrated. Dynamic force spectroscopy allows detecting a thin water layer of thickness ⁓1 nm, adsorbed on the outer surface of single TMV particles at RH < 60%.

Interface between Adjacent UV-Treated or Detergent-Treated Vaccinia virus Particles

2005 ◽  
Vol 11 (S03) ◽  
pp. 86-89 ◽  
Author(s):  
A. V. Cardoso ◽  
G. S. Trindade
Keyword(s):  
Atomic Force Microscopy ◽  
Vaccinia Virus ◽  
Particle Surface ◽  
Surface Interactions ◽  
Surface Interaction ◽  
Force Microscopy ◽  
Virus Particles ◽  
Atomic Force ◽  
Analysis Of The Images ◽  
Viral Surface

While investigating isolated or agglomerates of treated Vaccinia virus intracellular mature (IMV) particles in atomic force microscopy (AFM) equipment we noticed that in some occasions the enveloped particles had been totally disrupted, with the interior being spread around. We have also observed in these samples what appear to be some rather intriguing viral surface interactions. Instead of showing a clear division between individual virions the particles seem to be continuous at the interfaces that show coalescence. In order to understand what was happening we focused our attention on the analysis of the images of the interface between virions particles, trying to find out what was the explanation for such type of particle surface interaction and in which conditions it would take place.

scholarly journals Eggshell as a biomaterial can have a sorption capability on its surface: A spectroscopic research

2021 ◽  
Vol 8 (6) ◽  
pp. 210100
Author(s):  
Neslihan Kaya Kınaytürk ◽  
Belgin Tunalı ◽  
Deniz Türköz Altuğ
Keyword(s):  
Coturnix Japonica ◽  
Hydroxyl Groups ◽  
Spectroscopic Techniques ◽  
Desorption Process ◽  
Force Microscopy ◽  
Coturnix Coturnix ◽  
Alectoris Chukar ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Different Types

In this study, eggshell as a biomaterial was used as an adsorbent. This natural waste material is easy to access and cost-free. The surface of the eggshell with its porous structure showed affinity to adsorb damaging chemicals. In particular insecticides cause serious environmental pollution in agriculture, and this is a general problem all over the world. The aim was to remove insecticides from the environment and monitor the pesticides on the surface of eggshells by atomic force microscopy (AFM) images, Fourier transform infrared (FTIR) and UV/Vis spectroscopic techniques. Five types of eggshells, Denizli Hen, Coturnix Coturnix Japonica, Light Brahma Chicken, Alectoris Chukar and ISA Tinted -White , were used. Since they are commonly used, Cypermethrin, Deltamethrin and Indoxacarb were chosen as insecticide samples. The interaction effect of insecticides on the surface of eggshells was determined by AFM images; it was seen that the semispherical surface structures of the eggshells were flattened after adsorption. FTIR spectroscopy was used both to detect structural analysis and to determine the adsorption influence. In addition, UV-Vis spectroscopy was performed to evaluate the adsorption and desorption process. Porous media of different types of eggshells with an aqueous solution of insecticides had an electronegativity attractive surface which makes it an ideal adsorbent via hydroxyl groups.

scholarly journals Structure of Intracellular Mature Vaccinia Virus Visualized by In Situ Atomic Force Microscopy

2003 ◽  
Vol 77 (11) ◽  
pp. 6332-6340 ◽  
Author(s):  
A. J. Malkin ◽  
A. McPherson ◽  
P. D. Gershon
Keyword(s):  
Atomic Force Microscopy ◽  
Vaccinia Virus ◽  
Helical Surface ◽  
Force Microscopy ◽  
Virus Particles ◽  
The Core ◽  
Atomic Force ◽  
Afm Imaging ◽  
Intact Core

ABSTRACT Vaccinia virus, the basis of the smallpox vaccine, is one of the largest viruses to replicate in humans. We have used in situ atomic force microscopy (AFM) to directly visualize fully hydrated, intact intracellular mature vaccinia virus (IMV) virions and chemical and enzymatic treatment products thereof. The latter included virion cores, core-enveloping coats, and core substructures. The isolated coats appeared to be composed of a highly cross-linked protein array. AFM imaging of core substructures indicated association of the linear viral DNA genome with a segmented protein sheath forming an extended ∼16-nm-diameter filament with helical surface topography; enclosure of this filament within a 30- to 40-nm-diameter tubule which also shows helical topography; and enclosure of the folded, condensed 30- to 40-nm-diameter tubule within the core by a wall covered with peg-like projections. Proteins observed attached to the 30- to 40-nm-diameter tubules may mediate folding and/or compaction of the tubules and/or represent vestiges of the core wall and/or pegs. An accessory “satellite domain” was observed protruding from the intact core. This corresponded in size to isolated 70- to 100-nm-diameter particles that were imaged independently and might represent detached accessory domains. AFM imaging of intact virions indicated that IMV underwent a reversible shrinkage upon dehydration (as much as 2.2- to 2.5-fold in the height dimension), accompanied by topological and topographical changes, including protrusion of the satellite domain. As shown here, the chemical and enzymatic dissection of large, asymmetrical virus particles in combination with in situ AFM provides an informative complement to other structure determination techniques.

Comparative Observation of the Recombinant Adeno-Associated Virus 2 Using Transmission Electron Microscopy and Atomic Force Microscopy

2007 ◽  
Vol 13 (5) ◽  
pp. 384-389 ◽  
Author(s):  
Heng Chen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Atomic Force Microscopy ◽  
Vector System ◽  
Particle Analysis ◽  
Adeno Associated Virus ◽  
Force Microscopy ◽  
Virus Particles ◽  
Atomic Force ◽  
Transmission Electron

Adeno-associated virus (AAV) is a defective, nonpathogenic human parvovirus, which coinfects with a helper adenovirus or herpes virus. AAV's unique characteristics have made it an appealing vector system for gene delivery. AAV or recombinant AAV (rAAV) has been widely detected using negative stain transmission electron microscopy (TEM) but little has been detected using atomic force microscopy (AFM). In this article, we used AFM and TEM to observe the recombinant AAV-2 (rAAV-2) virus particles and applied statistical analysis to the AFM and TEM images. The results indicated that the rAAV-2 particle was a slightly elliptic particle close to round when it was detected by TEM (the mean length of major and minor axes of rAAV-2 particles was 24.77 ± 1.78 nm and 21.84 ± 1.57 nm, respectively), whereas when detected by AFM, the rAAV-2 particle was almost round. Even though the dimensions of the rAAV-2 particle exhibited a polymorphous distribution via off-line particle analysis of AFM, most of the rAAV-2 particles had a mean diameter of approximate 22.04 nm, which was similar to the results obtained by TEM. The results above suggested that AFM was important for accurately determining the average dimensions and distributions of virus particles.

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