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.

Alliance Protein Laboratories has been offering analytical ultracentrifugation analysis (both sedimentation velocity and sedimentation equilibrium) since 1999. We were the first contract lab in the US to offer these services, and to our knowledge still the only one with our own instruments in-house. APL has completed hundreds of AUC projects on proteins, peptides, nucleic acids, and other molecules. At A.P.L. all the analytical ultracentrifugations experiments and interpretation are done by John Philo, a recognized AUC expert who has 18 years experience in biotech product development, who pioneered new AUC software methods for analyzing biotech products and their interactions, and who has over 40 publications involving AUC measurements.

The sedimentation velocity and sedimentation equilibrium pages give further background about, and examples of, these two primary AUC techniques.

A.P.L. 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 2-4 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 Further Reading page):

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