Western blotting. Western blotting is a technique used to detect the presence of proteins or a specific protein in a mixture of proteins. Western blotting is used to determine the molecular weight of a protein. It is used to measure a relative amount of protein present in a complex mixture of proteins. So, these are two main objectives of the Western blotting that with the help of Western blotting we can determine the molecular weight of a particular protein and we can also determine our measure the amounts of a particular protein in a complex mixture of proteins. Western blotting have become one of the most common analytical tool for detection of viral proteins. As well as it is important for characterization of monoclonal and polyclonal antibody preparations, in determining the specificity of immune response to viral antigens. Western blotting is another type of the molecule biology technique or it is also called as technique of the biotechnology which is used to detect the presence of a specific protein in a mixture of proteins.