Ultrastructural postembedding immunogold labeling: applications to diagnostic pathology.

Ultrastructural postembedding immunogold labeling combines the advantages of routine transmission electron microscopy and detection of antigenic epitopes. As a result, morphologic findings can be accurately interpreted. Localization of morphologic correlates for the various antigenic determinants allows a good definition of the applications and limits of immunocytochemistry in diagnostic surgical pathology. In some cases, immunofluorescence and immunocytochemistry results at light- microscopic levels can be either validated or determined to be nonspecific. Application of ultrastructural immunolabeling to surgical pathology is no longer a distant possibility but rather a reality. The technique provides reliable and reproducible results. Image analysis and microanalytical techniques applied to ultrastructural immunolabeling serve objectively to analyze and clearly to portray results. This paper describes experience with ultrastructural immunolabeling of various renal diseases and neoplasms by means of an easy-to-use methodology that can be applied to the evaluation of specimens in a diagnostic surgical pathology laboratory.