Single molecule array (Simoa) assay with optimal antibody pairs for cytokine detection in human serum samples

Concentrations of cytokines in bodily fluids reflect the physiological or pathological state of the patient and can be used for prognosis, disease diagnosis or for monitoring therapeutic efficacy. However, in the bodily fluids of healthy or sub-healthy individuals, many cytokines are present at concentrations that are near or below the detection limits of current methods. Here we selected antibody pairs to be employed in the single molecule array (Simoa) assay for ten cytokines including GM-CSF, TNF-α, IFN-γ, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-7, and IL-10. The limits of detection (LODs) obtained were as low as 90 aM–6 fM. These assays allow detection of cytokines in healthy human serum samples at levels significantly below the detection limits of conventional ELISA assays. We provide detailed antibody pair information as well as the concentration profiles of ten cytokines in healthy human serum to serve as reference data for further ultrasensitive immunoassay development and future clinical applications.