Immunolocalization methods

The  availability  of  an  antibody or immunoglobulin  against  a  specific  antigen provides   the  opportunity   to  use  in which  antibody   in  a  range   of  immunological methods.  The site recognized through an antibody on the antigen is known as the antigenic determinant or epitope. The elevated specificity of an antibody for its epitope permits it to be used as a reagent for determining the location of the antigen in a cell (immunocytochemistry), for instance through coupling a fiuorescent label to the antibody and then using fiuorescence to localize its sites of binding through immunofiuorescence light microscopy. Even higher resolution can be get using antibody to that electron-dense particles, like as ferritin or colloidal gold, have been coupled and then viewing the binding sites using electron microscopy. Indeed, immuno-electron microscopy can map the position of protein antigens within macromolecular complexes like as ribosomes.