“…Experimental studies involving viruses often require viral stocks with high concentrations. While cell culture-based viral propagation systems are well developed for many viruses including CPV and FCoV, generating sufficient concentration of infective virus particles is not always possible by cellular propagation alone ( Ichim and Wells, 2011 , Richard and Aubry, 2018 ). Common virus concentration methods are based on high speed centrifugation, filtration, chemical precipitation, adsorption and affinity mechanisms; however, efficiency of the selected method is likely dependent on chemical and structural properties of the virus, condition of the sample/medium in which viral particles are retained, and the experimental purpose ( Ahmed et al, 2015 , Bofill-Mas and Rusiñol, 2020 , Ye et al, 2016 ).…”