A Nanopore Device to Discretely Measure Viral Particle Count and Functional Titer with Single-molecule Resolution

INV-21063

Background

An effective response to viral infections relies on rapid, selective, and sensitive detection of viruses. However, it is so difficult to quantify the concentration of packaged viruses in a sample that researchers use indirect metrics to assess concentration such as plaque-forming units (PFU). Other methods for viral analysis such as immunological assays, transmission electron microscopy, and PCR-based testing, are time-consuming and require large sample volume. Measurement of the physical titer of viral particles is not sufficient. The functional titer is important in determining the optimal transduction of cell lines by viral vectors in the manufacturing process so new methods are needed to overcome the limitations of current viral titration methods.

Technology Overview

Researchers at Northeastern describe a novel device for simultaneous assessment of the absolute viral particle count as well as the functional titer and replication efficiency of viral particles in a given sample. This device includes a combination of nanopore technology, which discriminates viral particles based on their biophysical properties, and single-molecule RNA fluorescence in situ hybridization (smFISH), which detects individual viral RNA expression in infected cells. Using this method, viral count and replication efficiency can be measured within a single experiment. Also, this method allows researchers to accurately control the number of viral particles that are exposed to the cell lines and to measure viral sized distribution.