Three-dimensional component labeling of digital confocal microscope images enumerates replication centers in BrdUrd labeled fibroblasts.

An algorithm (3Dlabel-1) for labeling three dimensional binary data sets has been developed. Serial optical sections are acquired using a confocal laser scanning microscope. After filtering and thresholding operations, contiguous elements in the three dimensional data sets are identified and labeled. The results are used to calculate the number and size of objects. Additionally, the labeled data are displayed by applying an algorithm (3Ddisp-1) to generate stereo pairs, in which label numbers are color coded and depth is cued by intensity. These procedures have been applied in investigations of the temporal and spatial distribution of replication centers throughout S phase in BrdUrd pulse labeled mouse fibroblasts.