The shell of protein or surfactant molecules that surround a dispersed nanotube, whether in biological fluids such as serum, or non-biological dispersion dominates many of the interactions of the nanotube with its environment. Measuring the structure and nature of the dispersing molecules will allow for predictions of properties such as the zeta potential, and will provide important information for addressing the effects and potential accumulation sites of dispersed nanotubes in the human body and in the environment. Recent work at NIST and elsewhere is just now beginning to produce nanotube samples with known length, purity, and chirality; these purified materials will be the starting point for measuring the structure and nature of the surrounding shell of adsorbed molecules.