Fig. 5.
We compared the bioluminescence produced by the luciferase co-labeled cells to the MR signal for each human amniotic fluid stem cells incubated with 100 μg/mL contrast agent for 24 h. (A) Bioluminescent imaging produced a strong signal, with the detection limit of this system was above 3906 cells, at which point lower cell numbers became statistically indistinguishable from the 0 cell controls. (B) The MR signal produced by the contrast agent-labeled cells had a lower maximum intensity than the bioluminescent signal, but with a lower minimum cell number detection limit. At the lowest evaluated cell number (61 cells), the MR signal produced by the cells was statistically distinguishable from the 0 cell controls.