Polymer Shape Anisotropy and the Depletion Interaction
  We calculate the second and third virial coefficients of the effective sphere-sphere interaction due to polymer depletion. By utilizing the anisotropy of a typical polymer conformation, we can consider polymers that are roughly the same size as the spherical inclusions. We argue that recent experiments can confirm this anisotropy. 
Mario Triantafillou and Randall D. Kamien