Ab173194

Enzyme‐linked immunosorbent assay (ELISA) kits were used to determine levels of CXCL9 (Abcam, Cambridge, UK; ab100595) and CXCL10 (Abcam, ab173194) in serum samples, following the manufacturer's instructions. Briefly, serum samples were diluted four times with diluent provided in the kit (for CXCL9) or used undiluted (for CXCL10). Serum samples and serial dilutions of human recombinant proteins were incubated in 96‐well plates precoated with antibodies detecting CXCL9 and CXCL10, respectively. Plates were washed and incubated with tetramethylbenzidine (TMB) solution provided by the kit for 30 minutes in the dark and with gentle shaking. STOP solution containing 0.15 M sulfuric acid provided by the kit was added to terminate the color development, and optical densities (ODs) were read at 450 nm. Standard curves were generated using OD values from serial dilutions of human recombinant proteins. Serum concentrations were obtained by plotting OD values of serum samples against the standard curves. All measurements were done in duplicates. The intra‐assay coefficients of variation (CVs) for the OD readouts from the ELISA assays were 7.63% for CXCL9 and 4.16% for CXCL10, both within the recommended range of less than 10%.