General Guidelines for Quality Assurance of Immunohistochemistry in a Mohs Lab.

BACKGROUND: The adoption of recently created protocols introduces Mohs laboratories to the principles of immunohistochemistry (IHC) performance validation and clinical laboratory regulations that are unique to these evolving technologies.

OBJECTIVE: To review Food and Drug Administration (FDA) IHC reagent classifications, IHC validation protocols, and quality assurance (QA) procedures and documentation needed in conjunction with IHC test guidelines.

METHODS: A focused review of IHC reagent classifications and guidelines in clinical testing laboratories was conducted using PubMed and FDA source documents.

RESULTS: The IHC regulation requirements are determined by the 3 FDA classifications of reagents: in vitro diagnostic reagents, analyte-specific reagents, and research use only reagents. To account for performance variability, IHC reagents benefit from routine validation and QA programs. We present our IHC adoption procedures for QA and documentation of IHC tests in a Mohs laboratory.

CONCLUSION: Incorporating a well-organized IHC validation and QA program into Mohs laboratories can increase regulatory compliance and reagent performance.