Analytical ultracentrifugation (AUC) is a fundamental and powerful tool for studying the size and shape of macromolecules in solution. It is particularly important for characterizing protein aggregation and determining the native state stoichiometry (quaternary structure). It is also a common tool for showing comparability of higher order structure (HOS). Recently APL has pioneered a new sedimentation equilibrium protocol that allows us to measure the weight-average mass of highly concentrated protein formulations (up to ~200 mg/mL).
Alliance Protein Laboratories has been offering analytical ultracentrifugation analysis, both sedimentation velocity (SV-AUC) and sedimentation equilibrium (SE-AUC), since 1999. We were the first contract lab in the US to offer these services. APL has completed hundreds of AUC projects on proteins, peptides, nucleic acids, and other molecules. At APL all the analytical ultracentrifugation experiments and interpretation are done by Drs. John Philo or Karl Maluf, both recognized AUC experts with extensive experience in AUC applications and data analysis and many publications involving AUC.
The sedimentation velocity and sedimentation equilibrium pages give further background about, and examples of, these two primary AUC techniques.
APL has two analytical ultracentrifuges: a Beckman-Coulter XL-I equipped with both absorbance and Rayleigh interference (refractive index) detection (picture) and also a Beckman-Coulter XL-A (absorbance data only). Turn-around for AUC analysis is typically 2-3 weeks.
Before even considering using another company for analytical ultracentrifugation analysis see questions you need to ask a biophysical lab.
Below are downloadable versions of a few of our presentations and publications about AUC (more can be found on the Resources page):
"New Approaches to Investigating the Self-Association and Colloidal Stability of Protein Pharmaceuticals at High Concentrations", Philo, J.S. & Maluf, N.K., poster, WCBP 2015
Philo, J. S. (2009). A critical review of methods for size characterization of non-particulate protein aggregates. Curr. Pharm. Biotechnol. 10, 359-372. [A PDF file is available but by request only (use the Contact form, and be specific about which article you want).]
"Aggregation analysis of therapeutic proteins, part 2: Analytical ultracentrifugation and dynamic light scattering". Arakawa, T., Philo, J. S., Ejima, D., Tsumoto, K., and Arisaka, F. (2007). Bioprocess International 5 (4), 36-47.
"Measuring Comparability of Conformation, Heterogeneity, and Aggregation with Circular Dichroism and Analytical Ultracentrifugation" , invited talk, State of the Art Methods for the Characterization of Biological Products and Assessment of Comparability, NIH, June 2003
"Sensitivity and Reproducibility of Protein Aggregate Analysis by Sedimentation Velocity", poster, WCBP 2005
an analytical ultracentrifugation method for measuring protein molecular masses in solution and for studying protein-protein interactions.
an analytical ultracentrifugation method that measures the rate at which molecules move in response to centrifugal force generated in a centrifuge.
