Diffusivities of several proteins or protein variants in nonadsorbing rigid-polymer and bonded-phase-silica chromatographic media were determined using pulsed-field-gradient NMR of both proton and fluorine nuclei. Solute size, pore size, and concentration all affect the intraparticle diffusivity. The intraparticle diffusivity of proteins is well represented by a hindered diffusion of a sphere in a long cylinder and a tortuosity factor of 2.0 for a ratio of solute diameter to pore diameter ranging from 0 to 0.3. An investigation of the effects of fluorine labeling on protein chemistry and hydrodynamics revealed that the extensive fluorine labeling denatured the protein, increasing its effective Stokes radius. The fluorine labeling did not, however, significantly alter the intraparticle diffusivity variation dependence on protein and pore sizes.