Development and Validation of Protein Microarray Technology for Simultaneous Inflammatory Mediator Detection in Human Sera

Table 1

Microarray lower limits of detection and quantification.

Biomarker	Lower limit of detection (LOD) (pg/mL)	Lower limit of quantification (LLOQ) (pg/mL)
Eotaxin-1	1.863	2.9
Eotaxin-2	0.739	5.9
IFN-γ	0.108	2.9
IL-1β	0.404	2.9
IL-4	0.600	2.9
IL-6	0.683	1.5
IL-8	0.535	1.5
IL-10	0.503	2.9
IL-17	0.445	5.9
IL-23	0.612	5.9
IP-10	0.458	5.9
MCP-1	0.284	5.9
RAGE	0.968	5.9
TGF-β	0.398	2.9
TNF-α	1.126	1.5
VEGF	0.744	1.5

The lower limit of detection (LOD) is the concentration of biomarker required to give a signal that is equal to the background (blank) plus three times the standard deviation of the blank. The lower limit of quantification (LLOQ) is twice the LOD value or the point where the coefficient of variation (CV), a measure of precision, falls below 20%, whichever is highest [17].