Human RBP4/Retinol Binding Protein 4 PicoKine® Quick ELISA Kit (120 minutes, 96 Tests) . Quantitate Human RBP4 in cell culture supernatants, serum, plasma (heparin, EDTA) and urine. Sensitivity: 10pg/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.