Detection of Monkeypox virus or viral DNA in prairie dog (Cynomys ludovicianus) tissues by viral plaque assay and real-time PCR. Tissues from infected prairie dogs and one sentinel prairie dog (PD24) were assayed for Monkeypox virus using an E9L Orthopoxvirus real-time PCR assay and 50% tissue culture infectious dose (TCID₅₀) plaque assay in Vero cells. Results are reported as TCID₅₀/PCR. Incongruous results between the two assays are italic, most often positive by PCR but not by cell culture; the only exception is indicated by boldface.