Shown are 0.5 micrometer thick confocal image of midplane sections of synchronized 3T3 fibroblasts pulsed for 2 min with CldU and labeled with FITC (green) followed by a variable chase time, and a sec...

Shown is a 0.5 micrometer thick confocal image of a midplane section of a 3T3 fibroblast pulsed for 5 min with BrdU and immuno-labeled with anti-BrdU antibodies. Replication is confined to discrete si...

Shown is a chromosome spread of a PtK1 cell pulsed with BrdU in early S phase, then treated with colcemid to arrest cells at metaphase. Spreads were immuno-labeled with FITC-conjugated anti-BrdU antib...