AbstractWestern blotting is a technique for detecting protein developed based on protein electrophoresis separation and antigen‐antibody detection. It combines the high resolution of SDS polyacrylamide gel electrophoresis with the specificity of antigen‐antibody reaction. The basic principle is that the protein components are separated by electrophoresis, then the protein on the gel after electrophoresis is transferred to the carrier membrane, and the area of the carrier membrane where protein is not adsorbed is blocked by a blocking reagent. Finally, the specific expression level of protein is analyzed by immunological detection. It overcomes the disadvantages of direct immunological analysis on polyacrylamide gel after electrophoresis greatly improves its resolution and sensitivity, and is widely used to detect the correctness of specific gene expression products or compare the relative variation of proteins’ expression.