Ultrastructural examination of HEL cells treated with His6-tag control peptide or with the combination of IR (6 hours before) plus TRAIL (1 μg/mL).

Note that in comparison with the normal morphology shown in the left panel, several HEL cells, on treatment with IR plus TRAIL, showed a characteristic chromatin cap (right upper panel) and the formation of micronuclei (right lower panel) typical of apoptosis. Representative results from 1 of 7 separate experiments are shown.