Timing of apoptosis in the MiCK assay. Typical plot of the OD versus time changes obtained from a microculture of cells exposed to an inducer of apoptosis is shown. Interval T_m(time to the maximum response) corresponds to the time when the maximum apoptotic response is achieved in the culture. Interval T_i(initiation time) corresponds to the time between adding an apoptosis inducer to the culture and the beginning of the steep rising portion of the curve. Interval T_d (development time) corresponds to the time between the beginning of the steep rising portion of the curve and its maximum. B is the best fit line of the steep rising portion of the curve; earliest point of intersection between the B line and the OD versus time curve is used as a uniform indicator for the beginning of the steep rising, apoptotic portion of the curve.