?s re variables in Stokes-Einstein eqn.

Dear Colleagues,
 	In the Stokes-Einstein equation for the diffusion coefficient for spherical
 molecules, is the radius of the molecule under consideration taken to be the
 hydrodynamic radius, the radius of gyration, or some other kind of radius?
 Also, in this equation is the viscosity taken to be the shear viscosity,
 intrinsic viscosity, kinematic viscosity, or some other kind of viscosity?
 	Along the same lines, if you measure the viscosity of a solution using a
 Ubbeholde capillary viscometer, are you measuring the kinematic viscosity, the
 shear viscosity, the relative viscosity, or some other kind of viscosity?
 	Kind address responses to me _directly_ at
 stuart.shapiro[ AT ]basileapharma.com
 Thanks in advance to all responders,
 S. Shapiro
 stuart.shapiro[ AT ]basileapharma.com