The reactivity of the antibody was checked by western blot against recombinant protein and immuno-enhanced chemiluminescence (ECL) against native CsMRP4 in crude extracts. The rCsMRP4-NBD1 and C. sinensis crude antigens were loaded onto SDS gels for electrophoresis and then transferred to nitrocellulose membranes (GE Healthcare Life Sciences, Seoul, Korea). The membranes were then blocked using 5% skim milk in PBS/0.05% Tween20, followed by incubation with mouse immune serum at 1:400 at 4 °C overnight and then with goat-anti-mouse-IgG alkaline phosphatase-conjugated antibody (Sigma-Aldrich, St. Louis, MO, USA) at 1:5000 for western blotting or with peroxidase-conjugated AffiniPure Goat Anti-Mouse IgG antibody (Jackson ImmunoResearch Inc., West Grove, PA, USA) at 1:10,000 for ECL at room temperature for 2 h. Normal mouse serum was used as the negative control. The recombinant protein was visualized by color developing in BCIP/NBT (Sigma-Aldrich, St. Louis, MO, USA). The native CsMRP4 was detected using a ECL solution kit (Bio Sesang, Seoul, Korea) and visualized using ImageQuant LAS 4000 (GE Healthcare Bio-Sciences, Amersham, UK).