Another empirical correlation for predicting the diffusion coefficient of large molecules and polymers was given by Polson and later used to look at biopolymers by Young et al.

\[D=\frac{9.4 \times 10^{-15} T}{\mu M_{w}^{1 / 3}} \quad \text { Polson equation }\]

where \(D\) has the units of \(\mathrm{m}^{2} / \mathrm{s}\). Use this expression to calculate the diffusivity of Fluorescein (Mw-332), IgG (Mw-150,000), and Phycoerythrin (Mw-240,000) in water at \(25^{\circ} \mathrm{C}\). Compare with data taken for diffusion in gels (mostly water) by de Beer et al. How close are the predicted and measured values?