Principles of Analytic Validation of Immunohistochemical Assays

Note: A validation study design may include, but is not necessarily limited to, such means as the following:
1. Comparing the new assay’s results with the expected architectural and subcellular localization of the antigen
2. Comparing the new assay’s results with the results of prior testing of the same tissues with a validated or verified assay in the same laboratory
3. Comparing the new assay’s results with the results of testing the same tissues in another laboratory using a validated or verified assay
4. Comparing the new assay’s results with results of a nonimmunohistochemical method
5. Comparing the new assay’s results with the results from testing the same tissues in a laboratory that performed testing for a clinical trial
6. Comparing the new assay’s results against percent positive rates documented in published clinical trials
7. Comparing the new assay’s results to IHC results from cell lines that contain known amounts of protein
8. Comparing previously graded tissue challenges from a formal proficiency testing program (if available) with the graded responses