Confocal analysis of dermal fibroblasts after heat shock stress. Cells were incubated at 45°C for 30 minutes, then either immediately fixed (time 0) or allowed to recover for 24 or 48 hours at 37°C. Cells were processed for indirect immunofluorescence labelling using anti-lamin A/C antibodies (panel A, a to f), anti-lamin B1 antibodies (panel B, g to r) and anti-vimentin antibodies (panel B j to i and p to r). Control and HGPS fibroblasts are indicated. (A) Fibroblasts were immunostained with anti-lamin A/C antibodies. Note the increased number of dysmorphic nuclei in HGPS fibroblasts compared to control 24 hours after recovery from heat shock. (B) Fibroblasts were immunostained with anti-lamin B1 and vimentin at times indicated after heat shock. Bar, 10 μm.