Table 1.

Limit of detection (LOD), limit of Quantification (LOQ), and coefficient of variation (CV) of PEdELISA for a panel of 4 cytokines. Here, the LOD and LOQ values were determined from the blank signal + 3σ and the blank signal + 10σ, respectively. The intra-assay CV was determined by quadruplicate measurements of five COVID-19 patient samples at the range of 6–600 pg/mL in both rapid and retrospective assay modes. The inter-assay CV was determined by taking the root-mean-square average of signals from 40, 200, and 1000 pg/mL assay standard in 10-day continuous measurements of COVID-19 patients.

Cytokine Type	Assay Blank (Average molecule per bead)	Assay Blank+3σ (Average molecule per bead)	LOD (pg/mL)	LOQ (pg/mL)	Intra-Assay CV (%)	Inter-Assay CV (%)
IL-1β	0.000143	0.000347	0.191	1.188	4.68	9.98
TNF-α	0.000179	0.000379	0.198	1.889	8.77	11.66
IL-10	0.000136	0.000378	0.350	1.552	5.70	9.63
IL-6	0.000189	0.000309	0.377	2.378	4.55	10.80