Human sTNFsR II ELISA Kit PicoKine® (96 Tests) . Quantitate Human TNFRSF1B in cell culture supernatants, serum, plasma (heparin, EDTA, citrate) and urine. Sensitivity: 2pg/ml. The brand Picokine indicates this is a premium quality ELISA kit. Each Picokine kit delivers precise quantification, high sensitivity, and excellent reproducibility. Only our most reliable and effective kits qualify as Picokine, guaranteeing top-tier results for your assays.