ab157283 does not bind to rhTNF-R1 and rhOX40:Fc in an ELISA assay. Method: A 96 well ELISA plate was coated O/N at RT with 100 µl of 1 µg/ml rhTNF-R1:Fc and 1 µg/ml rhOX40:Fc in PBS. 100 µl of ab157283 at 8 µg/ml were mixed with 100 µl 0.5% FCS in PBS in the first well and a series of 1:1 dilutions was prepared for the following wells. Binding of ab157283 to the receptor:Fc was detected after 1 hr incubation at 37°C using a goat anti-human HRP conjugated antibody (1/1000 dilution, 1 hr incubation). O-phenylenediamine dihydrochloride (OPD) was used as a substrate, and absorbance was measured at 490 nm in an ELISA reader.