INHIBITORY-ACTION OF CYTOKINE PRESERVATIVES ON CHEMILUMINESCENCE ASSAYS

Commercial tumor necrosis factor alpha (TNF alpha) reportedly stimulat es hydrogen peroxide-mediated chemiluminescence in macrophages. Howeve r, two commercially available forms of TNF alpha, a sodium azide-conta ining recombinant human TNF alpha and an azide-free murine TNF alpha, had opposite effects on a cell-free hydrogen peroxide chemiluminescenc e assay. Azide-free murine TNF alpha stimulated peroxide-associated ch emiluminescence, while the azide-containing human TNF alpha strongly i nhibited chemiluminescence. The inhibition of hydrogen peroxide chemil uminescence by the azide-containing TNF alpha was attributable to smal l quantities of sodium azide and bovine serum albumin used as preserva tives and carriers, respectively.