Viruses (inactivated or live-attenuated)

These complex vaccine products combine multiple serotypes, often with adjuvants. Asymmetric-flow field-flow fractionation (AF4) separates such complex samples by size with high resolution. Fractionation is followed downstream by multiple online instruments, including MALS, DLS, UV and fluorescence detectors, to complete the biophysical characterization.

Product validation

In the analysis of an influenza virus subpopulation shown here, both size and total particle concentration are quantified in detail by FFF-MALS. Comparison with results from TEM shows excellent agreement within 2% in virus concentration and 5% in size. A small dimer peak is also identified.

Complementary to FFF-MALS, the DynaPro™ Plate Reader provides high-throughput screening of hundreds of samples with respect to processing conditions and formulations. In addition to sizing, this technique is able to screen for thermal stability of virus samples and to determine viral particle concentration.

Additional literature

See http://doi.org/10.1016/J. JVIROMET.2007.04.008 to explore the comparison of FFF-MALS analysis to other methods such as transmission electron microscopy (TEM), atomic force microscopy (AFM), size exclusion chromatography followed by MALS (SEC-MALS), quantitative reverse transcription polymerase chain reaction (RT Q-PCR), median tissue culture dose (TCID50), and the fluorescent focus assay (FFA).