Assessing the comparability of cycle threshold values derived from five external quality assessment rounds for omicron nucleic acid testing

Table 4 PCR efficiencies of various laboratories using ORF1ab and N Ct values from EQA samples

Lab code	ORF1ab				N
Lab code	1/slope	intercept	r²	E (%)	1/slope	intercept	r²	E (%)
Tianlong nucleic extraction kit & BioGerm RT-PCR kit & Gentier PCR instrument
1110084	− 0.2827	43.86	0.9988	91.73	− 0.2737	45.56	0.9758	87.80
1110100	− 0.301	42.88	0.9796	99.99	− 0.301	44.72	1	99.99
1110155	− 0.1605	50.84	0.9995	44.71	− 0.301	43.64	1	99.99
110002B6	− 0.3345	42.39	0.9749	116.02	− 0.43	41.38	0.9423	169.15
Tianlong nucleic extraction kit & BioGerm RT-PCR kit & SLAN PCR instrument
1110051	− 0.2573	44.1	0.993	80.84	− 0.3627	41.83	0.9862	130.52
1110091	− 0.2509	44.89	0.9908	78.20	− 0.3763	41.77	1	137.85
Tianlong nucleic extraction kit & BioGerm RT-PCR kit & ABI7500 PCR instrument
1110006	− 0.301	42.05	0.9796	99.99	− 0.2676	44.71	0.9643	85.18
1110017	− 0.2737	43.36	0.9758	87.80	− 0.3345	43.57	0.9643	116.02
1110081	− 0.3763	40.04	0.9796	137.85	− 0.301	43.37	1	99.99
1110143	− 0.2573	43.99	0.9426	80.84	− 0.301	43.97	1	99.99
1110739	− 0.2509	44.89	0.9908	78.20	− 0.5017	40.65	0.9643	217.47

ISSN: 1743-422X