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Quantifying heterogeneous AAV loading using mass photometry

Empty/full AAV ratios and heterogenous loading in AAV analytics


Adeno-associated viruses (AAVs) are promising vectors for the delivery of recombinant DNA in gene therapies. One of the key attributes in AAV analytics is the AAV empty/full ratio, which is the proportion of viral capsids that contain the full recombinant DNA. Also of interest is the proportion of partially filled and overfilled capsids. Efficiently characterizing these attributes is vital for the development of AAV-based gene therapy products.


Mass photometry can support AAV purification protocols


Mass photometry can characterize AAV samples  with accuracy comparable to gold standard methods for AAV analytics. Mass photometers like the SamuxMP and the SamuxMP Auto are tailored to provide information about critical analytical attributes of AAV gene therapy samples, providing:

Accurate, single-particle characterization within the relevant mass range (0.5-6 MDa)

Measurement of AAV empty/full ratio, partially filled and overfilled capsids in less than 5 minutes

Requires as little as 5-10 µL of sample with a concentration of 10^11 particles/mL

These benefits make mass photometry an ideal technique for AAV analytics. The low sample consumption of mass photometry is beneficial during the development of AAV-based gene therapy products, when AAV sample quantities are restricted and very valuable.

To learn how mass photometry can speed up your AAV analytics

How to measure AAV empty/full ratios and partials with mass photometry

A plot showing a mass photometry measurement of an AAV sample including quantification of empty, full and partial AAV capsids

In this application note, you will learn how mass photometry can quantify AAV capsid loading, including AAV empty/full ratios as well as partials. You will also see how the results of mass photometry compare with those of gold standard AAV analytics methods. Download the app note and learn the full details.

Additional resources​


Harnessing mass photometry for AAV sample characterization in GMP-regulated environments

In this webinar you can learn how mass photometry measurement of AAV samples can be applied to GMP-regulated environments such as AAV gene therapy manufacturing.

Schematic showing the different features and services for GMP support provided by Refeyn
Image of a scientist loading sample onto a slide


Blog: Comparing analytical approaches for AAV characterization

Read this blog post to learn how mass photometry compares to other AAV analytical methods for measurements of empty/full and heterogeneously loaded AAV capsids.

To learn how mass photometry can speed up your AAV analytics

More Application Notes

Browse through our catalogue of application notes highlighting some recent case studies featuring mass photometry.

Investigating lentivirus titer with macro mass photometry


Mass photometry supports membrane protein purification protocols 

Characterizing protein oligomerization with automated mass photometry

Quantifying heterogeneous AAV capsid loading using mass photometry

Download application note

Download app note
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