Ultracentrifuga Analitica
ProteomeLab™ XL-A/XL-I

The ProteomeLab XL-A/XL-I in-solution characterization of proteins, oligomers, aggregates, particles, colloids, and small structures delivers accurate results you can rely on time and again. In-solution characterization allows for testing in native conditions, meaning you determine the sample testing environment that best suits your needs. The unique column-free separating technique of the ProteomeLab XL-A/XL-I measures the relative change in the distribution of molecular weights, providing an efficient way to measure heterogeneity, stoichiometry and self-associating systems. And, because the measurements are based on the first principles of thermodynamics and hydrodynamics, no standards or calibrations are required. As a result, you spend less time on setup and more time on discovery.

Our analytical ultracentrifuge platform offers a variety of customizable options, to meet your needs. Sensitive absorbance optics enable analysis of most samples, and interference optics can be used for low concentrations. Both systems can be implemented simultaneously, to maximize data acquisition in a single run. Additionally, we offer two different rotor configurations, and a variety of cell types, to enable multiple experimental designs. The wide range of rotational velocities also allow investigators to probe protein size, dimerization, and binding constants.
As mentioned, the analytical ultracentrifuge can be used for several types of experiments, but the two most widely used are sedimentation velocity and sedimentation equilibrium. Sedimentation velocity experiments are utilized to determine protein molecular weight and identify degree of dimerization. In a sedimentation velocity experiment, high rotor speeds are used to completely sediment all particles in solution. Protein dimers sediment at a different rate than single protein molecules owing to their higher weight, and since the analytical ultracentrifuge measures protein formulations in their native state, the degree of dimerization can be assessed to highly accurate levels.

Sedimentation equilibrium experiments use lower velocity, and assess the concentration distribution as a function of g-force applied. By measuring the concentration curve at several different g-forces, equilibrium binding constants can be measured. This approach provides several advantages to alternative technologies, which often require immobilization of one binding partner, and thus, can impact equilibrium binding by modify the conformation of the immobilized protein.

The analytical ultracentrifuge can also be used for high resolution size analysis of particles, and has been applied to samples as diverse as quantum dots, polymer nanoparticles, and carbon nanotubes. Since the instrument performs both separation and detection in a single experiment, it provides many advantages over ensemble techniques such as light scattering. Mass proportional size distributions can be obtained, which cannot be measured with ensemble approaches.

Beckman Coulter pioneered the field of analytical ultracentrifugation, with the first commercial model, and has continued to supply the field with high quality, powerful, and reliable instrumentation for several decades. Our current instruments continue this history of innovation, and are relied upon by academic and industrial customers throughout the world.