Antibodies serve as indispensable tools for both research and therapeutic applications. Their specificity in targeting antigens enables them to identify biomolecules in lab environments, or bind to crucial therapeutic targets.
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Mass photometry is a transformative technology for characterizing antibodies during production and offers rapid insights into antigen-antibody interactions, antibody aggregation and fragmentation
​Unlock rapid antibody analytics
During antibody manufacturing, efficient and reliable analytics are crucial for optimizing your antibody product. In-process analytics are especially valuable, particularly when interrogating the affinity of an antibody for its intended target, or when assessing the purity and stability of an antibody product. Traditional analysis methods can fall short of the mark when it comes to in-process analytics, often requiring a time-consuming workflow and substantial sample consumption to gain any valuable insight into the antibody sample.
Mass photometry is a novel analytical technique that analyzes antibody samples by determining the molecular mass distribution of antibodies at the single-molecule level. It can resolve antigen-antibody interactions, antibody aggregation, and fragmentation – all with minimal sample consumption and in a turnaround time of just a few minutes.
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Delivered by the TwoMP mass photometer, the technique is ideal for testing antibody samples at various stages during the production process, quickly delivering up-to-date data on affinity and sample integrity, with minimal disruption. Mass photometry can also quantify interactions of individual antibody molecules with target molecules.
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Figure 1: The monoclonal antibody Herceptin (trastuzumab) and its target, Her2, were measured individually and in mixtures, demonstrating the instrument’s ability to quantify the interactions of individual antibody molecules with target molecules.
Resolve antibody aggregation and fragmentation
Aggregation and fragmentation can significantly undermine the efficacy and safety of antibody-based products. Being able to detect these issues at various stages of product development is crucial for maintaining high-quality therapeutics. In addition to aggregation and fragmentation events, forced degradation studies are also routinely conducted to evaluate the stability of antibodies, ensuring that they perform as intended even under stress.
Mass photometry presents a sensitive and convenient solution for analyzing these key critical quality attributes of antibodies. It can detect contaminants within antibody samples down to picomolar concentrations, operating effectively across a broad range of buffers and experimental conditions. The technique also integrates seamlessly with other analytical techniques such as Size Exclusion Chromatography with Multi-Angle Light Scattering (SEC-MALS).
To further improve turnaround times in antibody analytics, Refeyn provides the Antibody Stability Software Module – which automatically quantifies aggregation in large sample batches in a fraction of the time required for manual analysis, providing statistical analysis for replicates.
The strengths of mass photometry make it a game-changer for fast, in-process analysis of sample purity and stability, transforming the landscape of antibody analytics by providing convenience, ensuring quality and accelerating development. 
Figure 2: Exposure of antibody samples to three different stress conditions (light, pH change, or peroxide). Samples were measured at 10 nM concentration using 5 μl on the TwoMP Auto. Results show that stress conditions 1 and 3 promote aggregation (specifically, the formation of dimers and trimers), relative to the control sample.
Reveal antigen-antibody interactions and more
Mass photometry excels in revealing critical insights into antibody-antigen interactions and a host of additional antibody dynamics. This sensitive and high-precision technique detects both individual elements and complexes within samples, even identifying low-abundance components (<1%). This capability allows for the rapid determination of the dissociation constant (Kd) of antigen-antibody interactions, providing essential data on the affinity of the antibodies produced.
Enhancing the capabilities of mass photometry, the MassFluidix HC microfluidics add-on for the TwoMP mass photometer enables the characterization of extremely low-affinity interactions. By rapidly diluting the sample prior to measurement, it exposes complexes that typically remain undetected at the standard nanomolar concentrations used in mass photometry. This approach offers a deeper understanding of antibody behavior, driving more robust and effective antibody development.
Figure 3: Mass histograms of a triplicate mass photometry measurement of a therapeutic antibody mixed with EGFR at a ratio of 2:1. Mass photometry detected each component separately as well as in complexes of different stoichiometries. The data from the measurements was used to estimate the binding affinities of the antibody:EGFR complexes (1:1=7.0 ± 2.0 nM; 1:2=25.3 ± 6.8 nM).
Mass photometry solutions for antibody analysis
For molecular mass measurements with unmatched sensitivity, speed and simplicity of use, a TwoMP mass photometer offers a wide mass range and single-molecule resolution.
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High-fidelity measurements of molecular mass
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Little sample required
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​Intuitive acquisition and data analysis software 
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​Easy setup – a compact, benchtop instrument with minimal installation requirements
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