Dot blot technique | principle , procedure and application |

Definition : Non-electrophoresed biomolecular samples (DNA, RNA, protein) are directly blotted on a nitrocellulose or nylon membrane as dots for identification of nucleis acid or protein.  Advantage: 1) Simple process of biomolecular identification because no electrophoresis is required and direct blotting on membrane . 2) sample from different source can be tested in a single run .  Disadvantage:  No information about the size of the target molecule . Procedure:  1) for nucleic acid           a) extraction of DNA or RNA          b) add to membrane           c) for DNA, denaturation           d) immobilization          e) hybridization          f) autoradiography 2) for protein           a) protein added to membrane           b) blocking           c) peimary and secondary antibody          e) detection  3) application:           a) identification of transgenic individual           b) estimation of protein concentration.