Quantification of Viral Families with Potential for Pandemic Emergence

Rapid and specific total virus particle enumeration is critical to the accelerated development and manufacture of vaccines during the emergence of novel pathogenic viruses. Traditional methods of virus particle quantification require intimate knowledge of the virus in advance of the generation of primers for polymerase chain reaction (PCR) and the creation/development of cell-based assays. In contrast, Sartorius’ Virus Counter 3100 was recently demonstrated to be effective in the enumeration of the human coronavirus 229E, using an established dual-dye (Combo Dye) approach in a 30-minute assay, as compared to the historical approaches that require days to complete or that are indirect.

We also demonstrated the ability to rapidly enumerate viruses from representative members from the Arenaviridae, Flaviviridae, Orthomyxoviridae, and Togaviridae families. In some instances, antibody detection may be preferred for its specificity and more robust response in avoiding issues with sample excipients and cell debris. The use of fluorescently-labeled antibodies for virus enumeration presents unique challenges. The small size of viruses brings antibodies in proximity as they bind and collect on the virus surface. This leads to the inter-molecular quenching of the fluorochromes. For this reason, the number of fluorochromes on each antibody needs to be carefully controlled. Sartorius developed a proprietary method to control for this effect.