OCI-AML3 cell loaded with cytoplasmic quantum dots. (Left) Representative cell at 6% O2. (Middle) The same cell after 2 minutes of reoxygenation with 21% O2. Four Qdot-containing particles leaving the cell can be seen in the picture. (Right) The cell loses fluorescence, indicating loss of Qdots. (100×/1.4 NA oil.)