Gene therapy is one of the most promising areas of biopharmaceutical research; however, analysis of viral capsids remains a big challenge.
Extremely limited sample availability makes it difficult to maintain high sensitivity and repeatability. Therefore, using the correct sample vials for capsid analysis via liquid chromatography is an important step toward highly reproducible results.
Characterization of adeno-associated viruses (AAVs) produced for gene therapy involves a number of analytical assays to determine their features and titer. The upstream process for production of AAVs is challenging, and for this reason, good recovery and extremely sensitive methods are usually required.
AAV analysis strategy: Use low-binding glass vials to prevent sample loss
In a recent experiment, Thermo Fisher Scientific demonstrated the benefit of using GOLD grade glass HPLC sample vials compared to polypropylene vials for viral capsid analysis. Contrary to oligonucleotide analysis, which is often run in conjunction with AAV analysis, AAV analysis requires high-quality glass vials instead of polypropylene vials.
Conclusions of the study
- If the AAV capsid proteins in the sample are stored in plastic vials, they adhere to the vial surface and are not available for sampling upon analysis, affecting the data robustness.
- GOLD grade glass vials offer significant advantages over plastic vials for AAV analysis.
- Analogous results were generated using different AAC serotypes, all reporting similar results when the two vial-typologies were compared during 12 hours of sample storage.
- The material of the HPLC vial affected not only the correct evaluation of the concentration of the viral capsids, but also the accuracy of the result and mainly the reproducibility of the results over a short period of time, with SEC-FLR peak intensity being reduced by ~90% in plastic vials.
- Bottom line: Consumables need to be properly evaluated when working and developing methods for this new class of biopharmaceuticals.
Read all the details of this study in this application brief.