Virus-like particles (VLPs)

Recombinant virus-like particles, which are designed to elicit an immune response in the same way that a traditional live-attenuated vaccine does, are typically comprised of a protein capsid, with nucleic acid cargo. SEC-MALS and FFF-MALS characterize both the capsid and cargo, while DLS is suitable as a quality-control tool to determine size, aggregation and viral physical titer.

Monitoring production process: measuring protein capsid and DNA cargo

The synthesis of VLPs involves three steps: 1) isolation of recombinant VLP from cell culture, 2) dissociation of the virus into pentameric capsomeres with removal of all DNA, 3) introduction of the DNA of interest and packaging into a newly formed VLP.

FFF-MALS is used to monitor this process, by separating and detecting fully formed capsids from aggregates, unassembled protomers, and capsomeres. The analysis informs on conformation, and, in the final step of the process, simultaneously measures protein and DNA molar mass to quantify the payload.