Differentiation of species of the genus Orthopoxvirus in a dot blot assay using digoxigenin-labeled DNA-probes

A dot blot assay using five different digoxigenin-labeled probes was established for specific detection and differentiation of four species belonging to the genus Orthopoxvirus. As little as 20 pg orthopoxvirus DNA can be detected, corresponding to approximately 8×10⁴ DNA molecules. A total of 37 orthopoxvirus strains and isolates of different origin were investigated and could be assigned to the species vaccina, cowpox, camelpox, and mousepox virus. These finding agree with their identification by biological means. Additionally, a simple procedure to isolate orthopoxvirus DNA directly from scab material was developed. This allows a fast classification without isolating the virus. © 1993.