Abstract
mRNA vaccines were highly effective in response to the COVID-19 pandemic, making them an attractive platform to address cancers and other infectious diseases. Many new mRNA vaccines in development are multivalent, which represents a difficulty for the standard assays commonly used to characterize the critical quality attributes of monovalent formulations. Here, we present a multiplexed analytical tool with nucleic acid microarray technology using the VaxArray platform that measures the identity and quantity of mono- and multivalent mixtures of naked mRNA and mRNA encapsulated in lipid nanoparticle formulations in under 2 h without any additional preparation steps, such as extraction or RT-PCR. Using a quadrivalent mixture of encapsulated mRNA constructs that encode for four unique proteins in a vaccine formulation, the VaxArray mRNA assay was demonstrated to be highly specific for each mRNA with sensitivity < 1 µg/mL. The quantification of individual mRNAs within the lipid nanoparticle mixture resulted in a precision of ≤10% RSD and an accuracy of 100 ± 9%.