MICROPLATE READERS


Photometry uses light scattering to analyse particles


purification, a typical AdV sample will contain full AdVs, empty capsids, helper viruses, and fragments. Full AdVs are functional and therefore desired, while empty capsids and fragments can decrease therapeutic efficacy. Furthermore, helper viruses can be immunogenic and pose safety concerns. Since molecular analysis techniques


struggle to discriminate between these populations, AUC has become the benchmark for determining empty and full AdVs by their density, but


the approach lacks scalability. Macro mass photometry can efficiently distinguish between particles in a sample, providing convenient means for quantifying impurities and monitoring the process during manufacturing, saving time and resources (Figure 2).


FUNCTIONAL LVV IDENTIFICATION Following a lentiviral vector (LVV) production process,


Figure 3: Physical and functional titers Figure 2: Sample purity scatter plot


the product containing infectious (functional) LVVs commonly retains a significant proportion of non-infectious vectors missing key genetic or protein components. Macro mass photometry can be leveraged to rapidly assess the amount of LVV present in a sample and distinguish LVV populations based on their functionality. The study data shown (Figure 3)


demonstrates a positive correlation between the percentage counts (determined by macro mass photometry) and physical titer measurements (determined by PERT assay). The percentage counts are also found to correlate positively with results from an infectivity assay, with the exception of measurements of the non-infectious samples as macro mass photometry is insensitive to infectivity. Overall, the results demonstrate the valuable utility of macro mass photometry in characterising LVV samples.. n


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