Imaging of fresh and DSP-fixed K562 cells. (a) Morphology of K562 cells before (left) and after (right) DSP treatment. DSP fixation did not cause detectable shrinkage or clumping. (b) Fluorescent staining of K562 cells after DSP treatment. In an overlay image of fixed K562 cells (right) stained with Hoechst 33342 (blue, left) and propidium iodide (PI; red, middle) before DSP treatment and then photographed 1 hour after fixation. Double-stained cells are circled in red (right). (c) Imaging of captured DSP-fixed K562 cells. Cells were captured on a Fluidigm C1 microfluidics IFC 2, 3 or 7 days after fixation, and imaged under bright field, and fluorescence for CTO (CellTracker Orange CMRA “ThermoFisher”), CTG (CellTracker Green CMFDA “ThermoFisher”) or Hoechst 33342.