[Cultivation of the transmissible gastroenteritis virus in a continuous cell line]

Cell cultures of the permanent cell line SPEV to which the transmissive gastroenteritis virus had already been adapted were used to culture the virus and carry out the virus-neutralization test. Use was made of a cell suspension of a variable density--300 and 500 thou cells per cm3. Both variants of the cell suspension were comparatively studied in terms of growth, the production of a monolayer, susceptibility to infection, and titer of the virus obtained, using 4 test tubes with the virus at various rates of dilution which were kept under observation daily, keeping a record of the infected and noninfected cell cultures. The amount of the virus was determined by titration. It was found that the monolayer was produced more rapidly in the suspension containing 500 thou cells/cm3. In that case infection could be performed at the 24th hour. The cytopathic effect was more pronounced, and the titer of the virus obtained was higher. Successful attempts were made with the virus-neutralization test with the infection of the cell cultures in suspension. Thus, the entire procedure was shown to be labour-saving as the time for investigation of the sera was shortened.