An HPLC-SEC-based rapid quantification method for vesicular stomatitis virus particles to facilitate process development

Abstract

Virus particle (VP) quantification plays a pivotal role in the development of production processes of VPs for virus-based therapies. The yield based on total VP count serves as a process performance indicator for evaluating process efficiency and consistency. Here, a label-free particle quantification method for enveloped VPs was developed, with potential applications in oncolytic virotherapy, vaccine development, and gene therapy. The method comprises size exclusion chromatography (SEC) separation based on high-performance liquid chromatography (HPLC) instruments. Ultraviolet (UV) was used for particle quantification and multi-angle light scattering (MALS) for particle characterization. Consistent recoveries of over 97% in the SEC were achieved upon mobile phase screenings and addition of bovine serum albumin (BSA) as sample stabilizer. A calibration curve was generated, and the method's performance and applicability to in-process samples were characterized. The assay’s repeatability variation was < 1% and its intermediate precision variation was < 3%. The linear range of the method spans from 7.08×108 to 1.72×1011 VP/mL, with a limit of detection (LOD) of 7.72×107 VP/mL and a lower limit of quantification (LLOQ) of 4.20×108 VP/mL. The method, characterized by its high precision, requires minimal hands-on time and provides same-day results, making it efficient for process development.