Sandwich antibody pairs for IL-20 were produced by Novo Nordisk A/S. Capture anti-IL-20 antibody was of the IgG1 isotype. Unspecific binding was assessed using a IgG1 isotype control from R&D Systems (MAB002, Minneapolis, MN, USA). IRDye-800 streptavidin conjugate was from LiCor Biosciences (Lincoln, NE, USA). Mouse, goat and bovine IgG were from Jackson ImmunoResearch (West Grove, PA, USA).
Purified cytokine antigen standards and sandwich antibody pairs for IL-1β (MAB601, BAF201), IL-10 (MAB2172, BAF217), IL-6 (MAB206, BAF206), and TNFα (MAB610, BAF210) were purchased from R&D systems. All capture antibodies were of the IgG1 isotype.