Simultaneous quantification of cells and nanomaterials by inductive-coupled plasma techniques.

We demonstrate that endogenous cellular magnesium levels can be used as an accurate determinant of total cell number by inductively coupled plasma techniques, increasing the throughput and reproducibility of nanoparticle-uptake studies. Uptake of either gold nanoparticles or quantum dots did not affect intracellular concentration of Mg. To demonstrate this technique, we show the decreased uptake of nano-urchins in A549 cells compared with gold nanospheres.