Analytical Ultracentrifugation (SV-AUC / SE-AUC)

AUC is highly suited for accurately determining important parameters of a drug substance, including molecular weight MW, diffusion coefficient, and sedimentation coefficient. As a first-principle method, AUC does not require reference standards for such determination. In particular, AUC is a powerful method that delivers the most accurate information on the (concentration-dependent) apparent molecular weight of the species in solution.

SV-AUC determines the content of low- and high-molecular-weights without any change in solution condition (if formulation components do not interfere with the detection). Thus, SV-AUC is the ultimate standard for determining the content of fragments, oligomers, aggregates and even nanoparticles in biopharmaceutical solutions.

The size range of AAVs (around 25 nm) is ideal for the analytical characterization by SV-AUC, particularly the quantification of empty vs. full capsids.

HP-SEC and AF4 are commonly used to determine fragments, oligomers, and aggregate content in (bio)pharmaceutical samples. While both techniques have numerous advantages, they also have a key fundamental limitation: in most cases, a change in solution condition (i.e., mobile phase) is required. This may alter a sample’s ‘true’ aggregate population before detection. SV-AUC can detect aggregates without any change in solution condition (if formulation components do not interfere with the detection). Thus, SV-AUC is often performed as an orthogonal method during the development of HP-SEC and AF4 to ensure the validity of their results.

SV-AUC and SE-AUC are very powerful methods for characterizing particulate species up to 200 nm, including viruses, virus-like particles, nanoparticles, liposomes, drug delivery systems and particle-based vaccines.

While many analytical techniques cannot directly measure highly concentrated samples (such as >100 mg/ml antibody solutions), SV-AUC and SE-AUC can be applied to them, for example, during formulation screening, without the need for sample dilution. By applying interference optics, highly concentrated samples can often be analyzed by AUC ‘as-is,’ enabling an unaltered view of a sample’s properties.

SV-AUC and SE-AUC analyze viruses, such as retroviruses, lentiviruses, and adenoviruses, for sizes up to 200 nm. We offer stability testing of viruses by AUC as a stand-alone service or as part of a virus formulation development project. Our AUC experts can also combine the power of AUC with orthogonal methods such as AF4 for enhanced insights.

As a first-principle method, AUC does not rely on (internal) standards and is thus well suited for the reliable determination of interaction parameters (KD, Stoichiometry, B22). It does so without needing protein binding or immobilization (as required for surface plasma resonance Measurements).

Coriolis applies the latest AUC technology (Beckman Optima III), and high-speed sample rotors allow our scientists to use centrifugal forces of 290,00 xg, which can sediment peptides down to 1 kDa, thus enabling their analytical characterization.

SE-AUC is a very powerful technique that delivers the most accurate information on the (concentration-dependent) apparent molecular weight of the species in solution.

We are proud to offer fluorescence detection as an option for AUC analysis. This allows for an active analysis of labeled molecules in a sample mixture, excluding interferences from other (unlabeled) species.

Coriolis employs AUC instruments with fluorescence detection. This enables in-depth analysis of protein-protein interactions with fluorescent tracers, making possible modeling scenarios and assays tailored to specific research questions.

AUC measures undiluted samples, does not have a stationary phase and utilizes high-sensitivity UV or fluorescence detection. Thus, SV-AUC and SE-AUC make analytical characterization of low-concentration samples (for example, diluted virus preparations) possible.