the animal has to be injected with Brdu and taken down at a very specific time frame like 1-2 hours after injection. contact me at my work email and I can scrounge one up. Nick(Rocky) Madary, HT,HTL(ASCP)QIHC Histology Manager, Medimmune Inc Cell-3012334950 Work-3013984745 Fax-3013989745\ company email madaryj <@t> medimmune.com