Intracellular IPA-3 amount determined using flow cytometry or fluorescence spectroscopy.

<p>(A, B) Results from flow cytometry measurements. The relative amount of IPA-3 was obtained as the increase in the mean fluorescence intensity (MFI) at 405/450 nm (excitation/emission) from samples incubated for 1 h with IPA-3 at 5, 10 or 20 μM extracellular concentration (white, light grey and dark grey bars, respectively) compared to the untreated control samples. (A) Cells were seeded at 2×10⁵ cells/ml, the figure shows means and standard deviations from 3 independent experiments. (B) JURL-MK1 cells were seeded at different cell density as indicated and incubated for 1 h with IPA-3. (C) MOLM-7 cells were seeded at 6×10⁵ (dotted line) or 1×10⁵ cells/ml (solid line) and incubated for 1 h with 20 μM IPA-3 (extracellular concentration). Cell aliquots (6×10⁵ cells from each sample) were lyzed and suspended in DMSO and fluorescence spectra were recorded with the excitation wavelength set to 405 nm. The background fluorescence (sample from the same amount of untreated cells) was subtracted. Closely similar results were obtained in repeated experiments.