In this sandwich ELISA, NAG-1 was captured from human serum using the following antibodies : anti-NAG-1/GDF15 (C terminal specific), anti-NAG-1/GDF15 (N terminal specific (PAN)), anti-NAG-1/GDF15 (H-variant) and anti-NAG-1/GDF15 (D-variant) polyclonal antibodies. Micro titer plates were coated with capture antibody at 1 ug/mL. 20 random normal human sera were performed. HRP conjugated anti-NAG-1/GDF15 (C terminal specific) antibody was added for detection at 100 µL per well at 1 ug/mL.