Pediatric Preclinical Testing Program (PPTP) – May 2012

In vitro testing: In vitro testing was performed using DIMSCAN, a semiautomatic fluorescencebased digital image microscopy system that quantifies viable (using fluorescein diacetate [FDA]) cell numbers in tissue culture multiwell plates [1]. Cells were incubated in the presence of drug for 96 hours. Mean fluorescence values were determined for each concentration tested and then normalized to the mean control fluorescence for the line to determine relative mean fluorescence values. For analysis of in vitro testing results, a non-linear regression, sigmoidal dose-response model was fitted using GraphPad Prism 5.03 to the relative mean fluorescence values vs. the log-transformed concentration (X) for the in vitro PPTP study data: