2.2.1. Sample preparation
The cells are seeded the day before analysis at 5–20 103 cells
in 100 ll per well in 96-well plates. After induction of cell death,
50 ll of cell supernatant is transferred to a new 96-well plate for
the LDH assay (see below), while the source 96-well plate containing
the cells is used for crystal violet staining at a pre-defined time.
After several gentle washes with PBS (up to 5 times), 100 ll of 0.1%
crystal violet solution is added to each well and the plate is incubated
at room temperature for 30 min. After several washes with
PBS (up to 10 times), 100 ll of acetic acid (33%) is added to each
well to dissolve the stained cells. Gently shaking the plates can
speed up the solubilization. Finally, absorbance is measured at
595 nm in a plate reader.