Any individual that meets the suspected case definition of monkeypox should be offered testing in appropriately equipped laboratories by staff trained in the relevant technical and safety procedures. Confirmation of monkeypox virus infection is based on nucleic acid amplification testing (NAAT), using real-time or conventional polymerase chain reaction (PCR), for detection of unique sequences of viral DNA. PCR can be used alone, or in combination with sequencing. The recommended specimen type for laboratory confirmation of monkeypox is skin lesion material, including swabs of lesion surface and/or exudate, roofs from more than one lesion, or lesion crusts.