Proliferation kinetics and cell lineages can be studied in whole mounts and macerates by means of BrdU/anti-BrdU technique.

S-phase cells in intact animals of the coelenterate species Eirene viridula, Hydractinia echinata, Hydra attenuata, and Hydra magnipapillata incorporate the thymidine analogue bromodeoxyuridine (BrdU) into newly synthesized DNA. BrdU-labelled nuclei divide and cells appear to undergo normal differentiation. Whole-mount preparations and macerated tissues were screened for S-phase cells by means of immunocytochemical detection of BrdU (Gratzner, 1982). It is demonstrated that spatial patterns of DNA replication can be evaluated easily. Cell lineages and pathways of cell migration could be traced.