Figure 1. Automated pre-processing of nuclear images. (A) Raw images were collected with multiple fluorescence channels (see methods): red and blue channels for Lamin A/C and DNA, respectively. (B) Matlab code segmented the Lamin A/C channel using a level set active contour algorithm to delineate individual borders; here, after 320 iterations. (C) The code then showed the raw and computed nuclear image and allowed input from user to adjust the contour manually by dilating and eroding. Multiple views of the segmented nucleus (left to right: binary segmentation, segmentation with an outline and the result after segmentation) allowed rapid visualization and the possibility for manual adjustment after the auto-segmentation. Pop-up boxes allowed user to confirm segmentations. Only satisfactory results were used for computation.