Cytopathic effects (cytocidal and cytoplasmic inclusions) in tissue culture
Death of CE in 4 to 10 days, depending on concentration of inoculum; cytocidal and cytoplasmic inclusions in tissue culture preparation.
Death of chicken embryo in 4 to 10 days, depending on concentration of inoculum
Elementary bodies in Gimenez-stained impression smears from infected yolk sacs of chicken embryos
Tumorigenicity: iodine-positive cytoplasmic inclusions in infected L or BGMk cells;