Abstract. To explore the effects of the novel properties of carbon nanoparticles (CNPs) on cytotoxicity, the adsorption of serum proteins in cell culture medium on multi-walled carbon nanotubes and three kinds of carbon blacks was investigated. The uptake of CNPs by Hela cells was measured quantitatively using 99mTc radionuclide labeling and tracing techniques, and the dependence of CNPs u…