Microtiter plate radioreceptor assay for tumor necrosis factor and its receptors in large numbers of samples

We developed a rapid radioreceptor assay for tumor necrosis factor (TNF) and its receptors by utilizing serum-coated 96-well plates. This assay has an advantage over the traditional tube assay in speed, number of simultaneous samples, and amount of material needed for the assay. As many as 200 samples were assayed in less than 3 h. The usefulness of this assay to determine TNF and its cell surface receptors and to screen for TNF inhibitors in large numbers of biological fluids from patients is demonstrated. This assay may also prove useful for determining the activity of competitive antagonists of TNF.