RAPID: Determination of the cross-over frequency of SARS-CoV-2 for rapid identification concentration

The University of Wisconsin-Milwaukee received an award to investigate an electrical trapping technique to rapidly concentrate SARS-CoV-2 virus to produce highly pure samples for the development of vaccines and therapeutics. Currently, purification through multiple in-series applications of filtration and centrifugation require up to two days to prepare virus samples. Unfortunately, the purity and viability of the separated viruses are still low after being collected by conventional methods. In this research, a correlation between the virus, nanoparticle size, and electrical dielectrophoretic trapping conditions is investigated to determine the best operating conditions to concentrate 80 ? 160 nm size SARS-CoV-2. The developed method will enable the rapid concentration of pure viruses from cell culture and patient samples. The concentrated samples will enhance the development of vaccines, cures, and rapid diagnostic methods for infectious diseases by rapidly supplying highly concentrated pure virus samples. Thus, the research will contribute to improve the public safety related to infectious diseases and economy in the diagnostics and therapeutics area. The developed method is also applicable to the concentration of biomolecules, including DNA, protein, cell lysed fragments and particles, in addition to viruses. Thus, this research will give a substantial improvement on the rapid characterization and applications of molecules in various disciplines, such as virology, genomics, proteomics, diagnosis, forensic science, in addition to vaccine and therapeutics development.

The novel dielectrophoretic nanoparticle manipulating method developed in this research can rapidly concentrate viruses into highly pure samples from virus-infected cell media and samples from patients. A charge polarization happens to a dielectric particle when the particle is exposed to an unevenly distributed electric field. The particle will move to either a dense or sparse electric field area depending on the given condition, such as electrical potential, frequency, and permittivities of the particle and medium. The direction of particle movement is inverted depending on the frequency; this is called cross-over frequency. The cross-over frequency varies depending on the characteristics of the particles, such as components, structure, charge, etc. In this research, the cross-over frequency of different bio-nano-particles, ranged from 60 to 500 nm size, will be investigated using heat-treated SARS-CoV-2 and nanoparticles. Initially, the cross-over frequency of different size nano-particles will be determined using dielectrophoretic traps, by modifying the applied potential, frequency, and particle size. Then, the same operating condition screening strategy will be applied to heat-treated SARS-CoV-2. Purity and efficiency of the isolated nano-particles and SARS-CoV-2 will be determined using the developed conditions. The developed method will circumvent the drawbacks that exist with the current serial treatment method used to separate virus, which are: time-intensive, laborious, complicated, and less effective. Consequently, this research will significantly enhance the understandings of the structures and characteristics of bio-nano-particles, such as live viruses, by supplying higher purity samples rapidly. Obtained results will be rapidly applied to other viruses and particles for further characterization and detection, as well as development of applications. This RAPID award to the University of Wisconsin-Milwaukee is made by the Division of Biological Infrastructure using funds from the Coronavirus Aid, Relief, and Economic Security (CARES) Act.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.