Figure 4.

(A–D) Intensity images of a dividing CHO-K1 cell that is stained with Calcium Green-1 AM and has chromatin marked by H2B-mCherry, in four nuclear stages identified as being structurally distinct from late mitosis to early interphase. Scale bar: 3 μm. (E–H) Pseudo-colored FLIM images of A–D, with the palette defined in the phasor plot of panel I. (I) Phasor distribution of the calcium experiment. The blue cursor highlights the phasor of the free form of the calcium indicator, and the red cursor indicates the bound form. (J) The average calcium concentration bound to chromatin over the duration of the experiment. With respect to images E–H, there is a decrease in local calcium concentration from 551 ± 104 nM, to 358 ± 182 nM, to 173 ± 67 nM, and to 36 ± 6 nM.