Table 2.

Detection of the analytical sensitivity of the FMDV RT‐iiPCR assay

(A)
Copy #	RT‐iiPCR Results (#positive/total)	R1 (Average ± SD)
100 000	5/5	4.81 ± 0.12
10 000	5/5	4.69 ± 0.12
1000	5/5	4.68 ± 0.08
100	6/6	4.62 ± 0.31
50	7/7	4.10 ± 0.80
20	5/5	4.36 ± 0.73
5	2/6	2.87 ± 2.05
0	0/7	0.99 ± 0.04

(B)
FMDV		RT‐iiPCR		RRT‐PCR
Isolate (Serotype)	Dilution	Result	R1	CT
A22/IRQ/24/64 (A)	10−5	+	4.96	34.91
	10−6	+	4.94	39.53
	10−7	−	1.00	No CT
O/UKG/11/2001 (O)	10−6	+	4.92	28.01
	10−7	+	4.77	31.84
	10−8	−	1.03	38.13
C1/Noville (C)	10−7	+	4.97	33.81
	10−8	+	4.94	No CT
	10−9	−	1	No CT
Asia 1/Shamir (Asia)	10−4	+	4.86	34.61
	10−5	+	4.95	No CT
	10−6	−	0.98	No CT
SAT1/KEN/4/98 (SAT1)	10−7	+	4.97	31.55
	10−8	+	4.8	35.83
	10−9	−	1.09	No CT
SAT2/SAU/1/2000 (SAT2)	10−6	+	4.95	32.08
	10−7	+	4.84	38.73
	10−8	−	0.99	No CT
SAT3/ZIM/4/81 (SAT3)	10−7	+	4.91	34.61
	10−8	+	4.93	No CT
	10−9	−	0.97	No CT

(A) Using in vitro‐transcribed (IVT) FMDV O1 Manisa/69 3D RNA. The IVT RNA was serially diluted in nuclease‐free water, and 5 μl of each dilution was tested in RT‐iiPCR assay. The assay was repeated a minimum of 5 times. (B) Using FMD viral RNA representing all 7 serotypes. R1 = R1 (signal/noise ratio) value. SD = standard deviation. In RRT‐PCR assay, a sample was considered positive when the threshold cycle (C_T) value was lower than 36. UKG = Channel Islands, ZIM = Zimbabwe.

This article is being made freely available through PubMed Central as part of the COVID-19 public health emergency response. It can be used for unrestricted research re-use and analysis in any form or by any means with acknowledgement of the original source, for the duration of the public health emergency.