Organ distribution of Qdots and ionic zinc after intravenous injection into the tail vein of mice. 65Zn activity was measured in organs and tissue. The percentage distribution of polymer-coated Qdots and ionic zinc 2 h (A) and 4 weeks (4 w) (B) after application is shown. The liver and spleen have the highest specific activity when Qdots are applied. The data are presented as mean values ± standard error of the mean.