rus
Issue #7-8/2024
A.I.Akhmetova, I.V.Yaminsky
THREE-DIMENSIONAL VISUALIZATION OF VIRUSES, BACTERIA AND CELLS IN THE EDUCATIONAL PROCESS
THREE-DIMENSIONAL VISUALIZATION OF VIRUSES, BACTERIA AND CELLS IN THE EDUCATIONAL PROCESS
DOI: https://doi.org/10.22184/1993-8578.2024.17.7-8.476.481
Scanning probe microscopy has proven itself as a unique device for solving problems in the field of virology, cell biology, biomedicine, regenerative medicine, materials science and microelectronics. This data can be used in scientific research, for teachers of natural sciences at school it is useful to expand the horizon of the educational program and show schoolchildren not only the world in an optical microscope or in formulas on the board. Atoms, molecules, proteins, viruses, bacteria and cells can be seen or even touched with an atomic force microscope, and this is a look at nanoobjects from a completely different angle.
Scanning probe microscopy has proven itself as a unique device for solving problems in the field of virology, cell biology, biomedicine, regenerative medicine, materials science and microelectronics. This data can be used in scientific research, for teachers of natural sciences at school it is useful to expand the horizon of the educational program and show schoolchildren not only the world in an optical microscope or in formulas on the board. Atoms, molecules, proteins, viruses, bacteria and cells can be seen or even touched with an atomic force microscope, and this is a look at nanoobjects from a completely different angle.
Теги: biomechanics living matter platelets scanning capillary microscopy stem cells биомеханика живая материя сканирующая капиллярная микроскопия стволовые клетки тромбоциты
INTRODUCTION
The scanning probe microscope (SPM) is a multitasking instrument for studying topography and physicochemical properties of samples with nanometre resolution. Due to the three-dimensional detail of SPM, it is possible to study proteins, viruses, bacteria, and cells with amazing precision and accuracy that is difficult to achieve in other research methods. Thanks to the use of FemtoScan Online software, even schoolchildren are able to process these data, which makes it possible to significantly diversify the educational process at school during science classes [1].
VIRUSES
For example, atomic force microscopy (AFM) can be used to examine tick-borne encephalitis virus quite safely. According to AFM data, the virus is located on the graphite surface in a dense layer, in some places presence of several layers of particles is noticeable, but in the frame size the virus covered the graphite surface quite uniformly (Fig.1).
Adsorption of virus particles on graphite and mica substrates was evaluated by contact AFM. The particles do not agglomerate or stick together on the mica surface. Viral particles are well anchored on the graphite surface, even after the sample was washed with 5 ml distilled water, the particles were not washed off the surface (Fig.2). Probably, they are partially retained by the graphite layers and remain on the surface.
We also scanned the viral particles monolayer surface with different applied force values: 10 nN, 20 nN, 15 nN (Fig.3). The height difference between the force value of 20 nN and 10 nN was almost 50 nm, which is comparable to the particle diameter. But at the same time, the particles themselves do not change their shape on the image, and no additional artefacts appear.
According to the results of the measurements we can say that the particles of tick-borne encephalitis virus even after inactivation remain quite hard, they are not deformed under different applied force, they are well fixed on the graphite surface, and they do not stick together in dense agglomerations. At adsorption on graphite and mica the particles lie down uniformly, do not aggregate, at high concentration viral particles tend to arrange themselves in a uniform layer.
BACTERIES
Bacterial cells are a favourite object to study using SPM. A well-prepared sample allows detailed visualisation of the cell wall, as well as evaluation of influence of biocidal substances on the nature of adsorption onto substrates. For example, when examining a sample of Pseudomonas aeruginosa, it is possible to assess the height of the bacterium, tendency to cluster on a substrate, or to evaluate the biocidal effect of a disinfectant on a cells colony. In this case, such a substance was oligohexamethyleneguanidine (OHMG), a broad-spectrum polymeric biocide that inhibits the various bacteria development of and fungi and prevents formation of biofilms [2]. Pseudomonas aeruginosa are Gram-negative, erect bacilli 1–3 µm in size and do not form spores. The shape of the bacteria is elongated, in the sample predominantly rounded. The bacteria in the control sample are represented mainly by colonies or dense small groups (Fig.4).
After exposure of the bacterial colony to the disinfectant, mostly single objects are found in the frame, but there is no structural damage to the cell walls (Fig.5).
BLOOD CELLS
Atomic force microscopy can be used to examine the physical properties and morphology of red blood cells.
The characteristic profile of the erythrocyte surface is shown in Fig.6. It is the shape of a biconcave disc. From the cross-section it is even possible to measure the depth of the erythrocyte depression, as well as to visually assess cell morphology for a given frame. We see only the classical erythrocyte shape in the field of view, there are no spherocytes, echinocytes, or acanthocytes.
From atomic force microscopy data, the parameters of each cell can be measured: mean height, maximum height, mean diameter, mean and RMS roughness of the cell area, perimeter and volume [3–5].
All these data can help both in the educational process in blood cell research and be useful for medical purposes in diagnosis.
CONCLUSIONS
Scanning probe microscopy provides many new advantages in the study of biological objects: viruses, bacteria, cells. With the help of data obtained on the atomic force microscope, it is possible to solve various tasks useful for mastering the future profession of an experimentalist. Three-dimensional visualisation allows to better understand the objects structure, their behaviour on the substrate, and the nature of the effect of biocidal substances on cells and others.
Scanning probe microscopy can be used as an additional tool in the educational process and as an important indicator in biomedical applications. The Scanning Probe Microscopy course at the Physical Department of Lomonosov Moscow State University provides a wide range of equipment, training programmes and presentations for the experimental study of nanoscopy.
ACKNOWLEDGEMENTS
This work was performed under the state order with the financial support of the Physical Department of Lomonosov Moscow State University (Registration subject 122091200048-7). FemtoScan Online software is provided by Advanced Technologies Center, www.femtoscan.ru. Image of stem cells was obtained by T. Sovetnikov.
PEER REVIEW INFO
Editorial board thanks the anonymous reviewer(s) for their contribution to the peer review of this work. It is also grateful for their consent to publish papers on the journal’s website and SEL eLibrary eLIBRARY.RU.
Declaration of Competing Interest. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
The scanning probe microscope (SPM) is a multitasking instrument for studying topography and physicochemical properties of samples with nanometre resolution. Due to the three-dimensional detail of SPM, it is possible to study proteins, viruses, bacteria, and cells with amazing precision and accuracy that is difficult to achieve in other research methods. Thanks to the use of FemtoScan Online software, even schoolchildren are able to process these data, which makes it possible to significantly diversify the educational process at school during science classes [1].
VIRUSES
For example, atomic force microscopy (AFM) can be used to examine tick-borne encephalitis virus quite safely. According to AFM data, the virus is located on the graphite surface in a dense layer, in some places presence of several layers of particles is noticeable, but in the frame size the virus covered the graphite surface quite uniformly (Fig.1).
Adsorption of virus particles on graphite and mica substrates was evaluated by contact AFM. The particles do not agglomerate or stick together on the mica surface. Viral particles are well anchored on the graphite surface, even after the sample was washed with 5 ml distilled water, the particles were not washed off the surface (Fig.2). Probably, they are partially retained by the graphite layers and remain on the surface.
We also scanned the viral particles monolayer surface with different applied force values: 10 nN, 20 nN, 15 nN (Fig.3). The height difference between the force value of 20 nN and 10 nN was almost 50 nm, which is comparable to the particle diameter. But at the same time, the particles themselves do not change their shape on the image, and no additional artefacts appear.
According to the results of the measurements we can say that the particles of tick-borne encephalitis virus even after inactivation remain quite hard, they are not deformed under different applied force, they are well fixed on the graphite surface, and they do not stick together in dense agglomerations. At adsorption on graphite and mica the particles lie down uniformly, do not aggregate, at high concentration viral particles tend to arrange themselves in a uniform layer.
BACTERIES
Bacterial cells are a favourite object to study using SPM. A well-prepared sample allows detailed visualisation of the cell wall, as well as evaluation of influence of biocidal substances on the nature of adsorption onto substrates. For example, when examining a sample of Pseudomonas aeruginosa, it is possible to assess the height of the bacterium, tendency to cluster on a substrate, or to evaluate the biocidal effect of a disinfectant on a cells colony. In this case, such a substance was oligohexamethyleneguanidine (OHMG), a broad-spectrum polymeric biocide that inhibits the various bacteria development of and fungi and prevents formation of biofilms [2]. Pseudomonas aeruginosa are Gram-negative, erect bacilli 1–3 µm in size and do not form spores. The shape of the bacteria is elongated, in the sample predominantly rounded. The bacteria in the control sample are represented mainly by colonies or dense small groups (Fig.4).
After exposure of the bacterial colony to the disinfectant, mostly single objects are found in the frame, but there is no structural damage to the cell walls (Fig.5).
BLOOD CELLS
Atomic force microscopy can be used to examine the physical properties and morphology of red blood cells.
The characteristic profile of the erythrocyte surface is shown in Fig.6. It is the shape of a biconcave disc. From the cross-section it is even possible to measure the depth of the erythrocyte depression, as well as to visually assess cell morphology for a given frame. We see only the classical erythrocyte shape in the field of view, there are no spherocytes, echinocytes, or acanthocytes.
From atomic force microscopy data, the parameters of each cell can be measured: mean height, maximum height, mean diameter, mean and RMS roughness of the cell area, perimeter and volume [3–5].
All these data can help both in the educational process in blood cell research and be useful for medical purposes in diagnosis.
CONCLUSIONS
Scanning probe microscopy provides many new advantages in the study of biological objects: viruses, bacteria, cells. With the help of data obtained on the atomic force microscope, it is possible to solve various tasks useful for mastering the future profession of an experimentalist. Three-dimensional visualisation allows to better understand the objects structure, their behaviour on the substrate, and the nature of the effect of biocidal substances on cells and others.
Scanning probe microscopy can be used as an additional tool in the educational process and as an important indicator in biomedical applications. The Scanning Probe Microscopy course at the Physical Department of Lomonosov Moscow State University provides a wide range of equipment, training programmes and presentations for the experimental study of nanoscopy.
ACKNOWLEDGEMENTS
This work was performed under the state order with the financial support of the Physical Department of Lomonosov Moscow State University (Registration subject 122091200048-7). FemtoScan Online software is provided by Advanced Technologies Center, www.femtoscan.ru. Image of stem cells was obtained by T. Sovetnikov.
PEER REVIEW INFO
Editorial board thanks the anonymous reviewer(s) for their contribution to the peer review of this work. It is also grateful for their consent to publish papers on the journal’s website and SEL eLibrary eLIBRARY.RU.
Declaration of Competing Interest. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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