Figure 6. Detection of the cytosolic Ca²⁺ change in P. falciparum by flow cytometry.

(a) FRET signals are represented by R_post/R_pre where R_pre is the YFP/CFP ratio before addition of inhibitors and R_post is the YFP/CFP ratio after addition of inhibitors. The mean and standard error of the mean of R_post/R_pre were obtained with 15 μM cyclopiazonic acid (CPA), 2 μM 2,5-Di-t-butyl-1,4-butylhydroquinone (BHQ), 7.6 μM thapsigargin (TG) and DMSO from 3 independent experiments. (b) Correlation of FRET signal values obtained by confocal microscopy and the values by flow cytometry. Maximum of FRET signal changes (R_max/R₀₎ from microscopic analysis and the FRET signal changes (R_post/R_pre) by flow cytometry are plotted. Linear regression line and the coefficient of determination (R² = 0.9956) are shown.