Figure 1.
Microscopy image of vero monolayers. Vero cells were inoculated with nasopharyngeal swab. (A) Vero cell cultures in negative control. 40× (A1), 200× (A2) micrograph. (B) Vero cell cultures in positive control. 40× (B1), 200× (B2) micrograph. (C) Microscopy image of Vero cells inoculated with nasopharyngeal swab sample of a patient 33 days after diagnosis. No cytopathic effect was seen. 40× (C1), 200× (C2) micrograph. Virus stock used for positive control was obtained from the Centers for Disease Control and Prevention (KCDC, Seoul, Korea), the virus titer was 2.2 × 105 PFU/mL and the Ct value was 11 (KCDC03 43326).