Westernblotting, also known as western blotting, is a method to detect protein in complex samples according to the specific binding of antigen and antibody. This method is a new immunobiochemical technique developed on the basis of gel electrophoresis and solid-phase immunoassay. Because of the high resolution of SDS-PAGE and the high specificity and sensitivity of solid-phase immunoassay, protein blot has become a routine technique for protein analysis. Protein blot is usually used to identify protein and can be used for qualitative and semi-quantitative analysis of protein. Combined with chemiluminescence detection, the expression differences of the same protein in multiple samples can be compared simultaneously.