Spatio-temporal response of Capan-2 spheroid to gemcitabine and Chk1 inhibitor. Analysis of gemcitabine response in presence and absence of CHK1 inhibitor was done on 5 μm frozen sections of Capan-2 spheroids treated 16 h with 10-7 M gemcitabine alone, 2 10-8 M CHIR-124 alone or the combination of gemcitabine and CHIR-124 at these same doses. DNA damage was revealed by immunodetection of phosphorylated of γH2AX, S phase checkpoint was monitored on Capan-2 spheroid expressing the geminin-mAG Fucci green probe and apoptosis was analyzed by immunodetection of cleaved form of PARP. Images were collected using a X10 objective. The scale bar corresponds to 100 μm. Results shown are representative of the examination of 3 sections from 5 spheroids. Each experiment has been repeated 3 times.