Developing an Anion Exchange Chromatography Assay for Determining Empty and Full Capsid Contents in AAV6.2

Area of Science:

• Biotechnology
• Gene Therapy
• Analytical Chemistry

Background:

• Adeno-associated virus (AAV) vectors are key gene delivery systems in clinical trials.
• Empty AAV capsids, production by-products, can affect product safety and efficacy.
• Accurate characterization of empty capsids is vital for AAV process development.

Purpose of the Study:

• To develop a quality control (QC)-friendly assay for quantifying empty and full AAV capsids.
• To establish a reliable method for assessing AAV product purity.

Main Methods:

• Development of an anion exchange chromatography (AEX) assay using AAV serotype 6.2.
• Characterization of empty and full capsid percentages.
• Validation of the assay for QC implementation.

Main Results:

• The developed AEX assay can detect as low as 2.9% empty capsids in AAV6.2 samples.
• The assay requires minimal sample volume (microliters) and a minimum titer of 5 × 10^11 vg/mL.
• The method is automatable, easy to deploy, and successfully used for in-process and release testing.

Conclusions:

• Anion exchange chromatography provides a robust and QC-friendly method for determining empty AAV capsid percentages.
• This assay supports the development and quality control of AAV-based gene therapies.
• The method enhances the ability to ensure the safety and efficacy of AAV products.