Quantitation in immunohistochemistry. A research method or a diagnostic tool in surgical pathology?

Quantification of immunohistochemical methods is feasible by two ways, namely microscope photometry and TV densitometry. The rapid progress of computer technology argues largely in favour of the second system. From the immunohistochemical methods either ABC, the PAP or the APAAP method should be chosen. Diaminobenzidine is the H2-donor of choice for the peroxidase mediated systems, whereas Fast Red TR or Neufuchsin can be used with the APAAP system. The test efficiency, and the precision of measurements should be investigated in each laboratory doing quantitative immunohistochemistry. Low levels of coefficients of variation (CV) should be reached for one field of interest. Examples of introducing the method of quantitative immunohistochemistry in a routine laboratory are discussed. The demonstration of either a steroid receptor or a proliferation marker, such as PCNA or Ki67, are seemingly of the greatest clinical interest.