Case study: Quantification of vaccinia virus in murine tissue samples by plaque assay
Scientific challenge
Developing a proprietary vaccinia virus strain
A pharmaceutical company developing a proprietary vaccinia virus strain required a robust and reproducible method to quantify infectious virus recovered from a large number of murine tissue and blood samples.
The project required VRS to establish the client’s existing plaque assay at our laboratory and demonstrate that it could be transferred successfully while maintaining the expected assay performance. The validated workflow would then be used to quantify infectious virus recovered from multiple organs and blood samples collected during their preclinical programme.
Virus |
Vaccinia virus (VACV) |
Project |
Quantification of a proprietary vaccinia virus strain in murine tissues and blood |
Assay |
Plaque assay |
Client |
Large pharmaceutical company |
Stage |
Preclinical research |
Services |
Technical transfer, assay qualification, matrix interference assessment, virus extraction, viral quantification |
Related expertise |
Vaccinia virus, plaque assays, assay qualification, tissue processing, viral quantification |
Key considerations
Reliable results across biological matrices
The assay needed to generate reliable quantitative results across a wide range of biological matrices, whilst maintaining consistency with the client’s established methodology.
Key considerations included:
- ensuring successful technical transfer of the existing plaque assay from the client’s laboratory to VRS,
- demonstrating reproducible assay performance following transfer,
- assessing potential interference from different murine tissue and blood matrices,
- developing an appropriate workflow for virus extraction from multiple organs,
- processing and analysing a large number of samples without compromising data quality or delivery timelines.
The scale of the study made consistency and efficient sample processing particularly important, as variability introduced during sample preparation or assay execution could affect interpretation across the dataset.
Our Approach
Coordinated processing
VRS first performed a detailed technical transfer of the client’s plaque assay, ensuring that the methodology, experimental parameters and acceptance criteria were appropriately established at our laboratory.
Following transfer, the assay was qualified to demonstrate that VRS could reproduce the expected results consistently and generate reliable quantitative measurements using the client’s proprietary vaccinia virus strain.
Before analysing study samples, VRS conducted a matrix interference assessment to determine whether components of the different murine organs and blood samples could affect viral recovery or plaque formation. This provided confidence that subsequent measurements would reflect infectious virus present in the samples rather than matrix-related effects.
The established workflow was then applied to the study samples. Viral material was extracted from a large number of individual murine organs and blood samples before infectious virus was quantified using the qualified plaque assay.
The study involved substantial sample numbers and required coordinated processing across sample extraction and virological analysis. VRS maintained consistent experimental procedures throughout the programme to ensure that results generated across the full sample set were comparable and reproducible.
Outcome
Completed within short timeline
VRS successfully transferred and qualified the client’s plaque assay and established its suitability for quantifying infectious vaccinia virus in the relevant murine tissue and blood matrices.
The subsequent extraction and analysis of a large number of samples generated a comprehensive dataset of infectious virus levels across the tissues investigated.
Despite the scale of the study, VRS completed the work within the short agreed timeline while maintaining a high standard of assay performance, sample handling and data quality.
VRS INSIGHT
Provided a complete workflow
For large preclinical virology studies, establishing the assay is only one part of the challenge. Confidence in the resulting dataset depends on demonstrating that the assay is reproducible, that biological matrices do not compromise the measurement, and that sample processing remains consistent across a large study.
By combining technical transfer, assay qualification, matrix assessment and high-throughput sample processing, VRS provided a complete workflow for reliable quantification of infectious vaccinia virus from complex biological samples.
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