NC membrane is the reaction membrane in the immunochromatographic test strip and the most critical part of the whole test strip. After the NC membrane is assembled with the sample pad, binding pad and water absorption pad, when the Iiquid of the sample flows to the reaction membrane, the complex of the detector and binding protein will contact with the antigen / antibody on the reaction line at the molecular level, Finally, the results can be seen by our naked eyes or detected by machines, so it has a wide scope of applications in the fields of biomedicine, animal husbandry and food safety.