There is a high frequency of detectable HHV-6 viral load in SCT recipients and it may lead to an increased risk of fatal symptomatic disease [19] . The availability of quantitative real-time PCR means that results are available in a clinically helpful time-frame, which should assist with implementing timely therapeutic intervention and assessing response to treatment. Further investigation to monitor HHV-6 reactivation on a larger group of SCT recipients will be important in improving outcome for these patients. The infection of primary avian tracheal epithelial cells with infectious bronchitis virus Here we introduce a culture system for the isolation, passaging and amplification of avian tracheal epithelial (ATE) cells. The ATE medium, which contains chicken embryo extract and fetal bovine serum, supports the growth of ciliated cells, goblet cells and basal cells from chicken tracheas on fibronectin- or matrigel-coated dishes. Non-epithelial cells make up less than 10% of the total population. We further show that ATE cells support the replication and spread of infectious bronchitis virus (IBV). Interestingly, immunocytostaining revealed that basal cells are resistant to IBV infection. We also demonstrate that glycosaminoglycan had no effect on infection of the cells by IBV. Taken together, these findings suggest that primary ATE cells provide a novel cell culture system for the amplification of IBV and the in vitro characterization of viral cytopathogenesis. Embryonated egg inoculation is commonly used to amplify avian RNA viruses. Successful viral replication mainly depends upon viral adaption to and replication in the cells of the embryonic and extraembryonic tissues. Growth retardation and malformation of the embryo are the main indicators of viral reproduction in this system and signal the proper period for harvesting the amplified virions from the amniotic or chorioallantoic fluids.