<prompt> Analysis of protein antigen is bySouthern blotNohern blotWestern blotEastern blot  <response>: The western blot is a widely used analytical technique used in molecular biology, immunogenetics and other molecular biology disciplines to detect specific proteins in a sample of tissue homogenate or extract. Ref : Ananthanarayana textbook of Microbiology 9th edition Pgno : 579 