Examination of growth rate of permanent DBT cells Equal numbers (1 3 10 5 ) of DBT-VEC, DBT-A1 and DBT-A1DC cells were plated in 10-cm culture plates and maintained in culture medium for 4 days. Cells were trypsinized, stained with Trypan Blue (Gibco-BRL, Grand Island, NY) and counted at 24-h intervals with a hemacytometer (Hausser Scienti®c, Horsham, PA).