The immunogold-silver staining method. A powerful tool in histopathology.

Immunostaining of routinely fixed, wax embedded tissues may present problems to the pathologist since destruction of antigens can lead to false negative results. In an attempt to overcome this problem, we have compared the results of the standard peroxidase anti-peroxidase (PAP) method with those obtained using the newly developed and very sensitive immunogold-silver staining (IGSS) method. Sections from routine histopathological material as well as from normal tissue specimens were used in the comparison. Antisera to a variety of antigens commonly employed in pathology were used, including regulatory peptides and a range of other markers. In all cases the IGSS method was found to give superior or at least equal results to those obtained with the PAP technique. In some cases staining was obtained with IGSS method when the PAP technique gave no result. The intense black reaction product allowed much easier and more rapid screening of immunostained preparations as well as permitting sections to be counterstained with routine histological stains such as haematoxylin and eosin. It is therefore suggested that immunogold-silver staining is a valuable technique for the pathologist, particularly when examining overfixed or badly processed tissues.