Abstract
In a study of the morphogenesis of respiratory syncytial (RS) virus, we have observed unusual tubular structures, both in infected and control HEp-2 cells. Tubular structures of similar morphology were described in HEp-2 cells infected with a type 1 foamy agent by Clarke, Attridge & Gay (1969). The fact that these tubular structures have been observed in uninfected control cells is something new to our knowledge and deserves mention.
We have used the HEp-2 cell line obtained from Dr André Chagnon of our Institute at the 129th passage level. This cell line was first established by Moore, Sabachewsky & Toolan (1955) from a human carcinoma of the larynx; it was purchased from Flow Laboratories Inc., Rockville, Md, U.S.A. Maintained in our laboratories a few more passages before use for electron microscopy, this cell line was grown in medium 199 prepared in Hank's solution (199-H) 45%, minimum essential medium in Earle's solution (MEM-E) 45%, and foetal calf serum 10%.