Can we measure the cell cycle of the administered cells from outside the body, while the recipient is still alive ? Preferably, by using a device such as IVIS that can read fluorescent labelling in the body non-invasively.
In this paper, cells incorporating a reporter called Fucci are transplanted into mice in which a skin-flap window was created. The mice were observed in CLSM while alive through the skin-flap window. As a result, the cells were individually imaged at very high resolution.
Fucci-explessing cells change colour as the cell cycle progresses, so the researchers were able to visualise which stage of the cell cycle each transplanted cell was in.
However, this method is invasive. So we need a simpler method. The required resolution should give what proportion of cells are in which stage of the cell cycle. We don't need the single cell resolution.