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O. V. Gradov, Yu. V. Zhulanov, P. Yu. Makaveev
«Optical Ultrastructural Virometry Using Optoelectronic Aerosol Counters and Laser Aerosol Spectrometers. Is It Possible to Pose the Problem Correctly? »
0487–0512 (2021)

PACS numbers: 07.60.-j, 42.60.-v, 42.62.-b, 82.70.Rr, 87.15.-v, 87.64.-t, 87.80.-y

Along with the optical cytometry based on the analysis of a fluorescent light signal, in recent years, a complex of virometry methods has emerged, in particular, flow virometry (by analogy with flow cytometry). Because of this, the main emphasis is usually made on the molecular-biological aspects, rather than on ultramorphological and dimensional (size) differences of viruses. However, the universal method cannot be based on the specific selective carriers, especially for the supramolecular systems with a high specificity of complementary binding, which include the genetic mechanisms of viruses. It is impossible to create a system capable recognizing all types of viruses. Viruses with non-identical scattering indicatrices, i.e., with different morphological and geometrical capsid types (spiral, icosahedral, elongated and complex ones) can be recognized/distinguished only within the approximation—diffraction fingerprinting, matching the corresponding virus geometry as a result of the calibration process using the test particles with adequate size and geometry. Despite the widespread simplification extrapolating the Mie theory of the light scattering to the almost full range of particle sizes, including Fraunhofer diffraction as a special case, it is well known that the Mie theory is invalid at small diffraction parameters. Diffusion Aerosol Spectrometer DAS model 2702 can operate in the monitoring mode, including the particle size range from 3 to 200 nm. Since the size of most viruses ranges from 20 nm to 300 nm, there are no fundamental limitations for measuring a wide range of the most common viruses. As for the particles beyond 200 nm, as well as the extreme cases of the micron aggregates (Pandoravirus sp., Pithovirus sp., Filoviridae, etc.), the DAS 2702-m model can be equipped with the submicron particle measurement module operating in the range from 0.2 to 10 microns. Accordingly, if there was a sufficiently wide-range measurement method with the calibration for specific geometric prototypes, then the technique providing an aerosol dispersed viral morphological analysis would have covered most of the typical viruses.

Keywords: optical virometry, flow virometry, virus sizing, diffusion aerosol spectrometer, laser aerosol spectrometer, Stokes–Einstein equation, Mie scattering theory, Fraunhofer diffraction, qualimetric criteria, optoelectronic aerosol counter

https://doi.org/10.15407/nnn.19.03.487