Immunohistochemistry (IHC), in situ hybridization (ISH) and other slide-based molecular tests are the more complex and clinically valuable tests performed in the histology laboratory. Advances in laboratory automation have made these technologies more accessible in the routine diagnostic workflow. However, staining quality and consistency is still variable within and between laboratories. Interestingly, the largest source of variability observed in an IHC stain is not due to the staining process, but due to the pre-staining processes as shown in Figure 1.
Standardization of fixation, grossing and tissue processing with advanced staining techniques are now widely recognized as critical in maintaining consistent, high quality stains. This is reflected in the 2013 ASCO/CAP guidelines for