FAQ

What is hydrodynamic radius (Rh)?

The hydrodynamic radius determined by our Fluidity instruments is the Stokes radius, or the size of a hard spherical particle that diffuses at the same rate as the protein(s) detected.

For proteins, this is largely determined by the molecular weight, but shape also plays a role, with compact, well-folded proteins diffusing faster than extended, poorly folded proteins, and thus having a smaller hydrodynamic radius. The size determined by gel permeation or size exclusion chromatography is also the hydrodynamic radius.

Click here for details on how to convert hydrodynamic radius of proteins to molecular weight

Back to FAQs