Figure 9. Increase in polyamine concentration leads to increased chromatin compaction in permeabilised cells.

(A) FLIM images of permeabilised Hela^H2B-2FP cells with increasing Spermidine³⁺ concentration showing a reduction in EGFP fluorescence lifetime. The increase in compaction is also seen with the fluorescence intensity image. (Scale bar –10 µm) (B) FLIM images of permeabilised Hela^H2B-2FP cells with increasing Spermine⁴⁺ concentration showing a reduction in the calculated EGFP fluorescence lifetime. The increase in compaction is also seen with the fluorescence intensity image. (Scale bar –10 µm) (C) The average fluorescence lifetime normalised to control values of the Hela^H2B-2FP cells are plotted against the Spermidine³⁺ concentration. Error bars indicate standard deviation for values calculated for 15 cells from 3 independent experiments. (D) The average fluorescence lifetime normalised to control values for each the cells are plotted against the Spermine⁴⁺ concentration. Error bars indicate standard deviation for values calculated for 22 cells from 3 independent experiments.