Table 1.

SARS-CoV-2 cases and virus isolation

	Cq value of specimens
Case	N set*	N2 set*	Virus isolation	Days (CPE appearance)	Virus titer at 3 d p.i., TCID50/mL
V-009	33.87	30.87	No	>6 d	u.d.
Wk-177	u.d.	35.08	No	>6 d	u.d.
I-004	34.52	31.66	Yes	3 d	2.2 × 107
V-029	32.85	28.80	Yes	3 d	4.6 × 106
Wk-012	33.53	29.60	Yes	3 d	2.2 × 107
Wk-501	27.35	21.76	Yes	2 d	6.8 × 106
Wk-521	29.68	24.41	Yes	2 d	6.8 × 107

u.d.: undetermined.

^*The real-time RT-PCR primers and probe sets (N and N2 sets) are described in Shirato et al. (10).