Among the most highly demanded services offered by the Histology and Research Laboratory is the optimization and performance of IHC assays.
BLS has extensive experience optimizing IHC staining methods for research protocols. IHC is a robust methodology for the quantification of protein expression. IHC may be optimized for tissues processed by routine surgical pathology methods (formalin fixation followed by processing into paraffin-embedded tissue blocks). It is increasingly recognized that IHC-based methods to validate gene expression patterns that are identified using genomics techniques may represent more robust clinical assays than measurements of gene expression by other means, such as at the level of RNA, due to relative stability of the protein products of genes in routinely processed tissue samples and the retention of tissue architecture which aids in interpretation of expression results. BLS uses a matrix-based approach to test variable conditions until optimal staining is achieved. Variables included in typical IHC optimization matrix include pH [citrate (pH 6), EDTA (pH 8), and Tris (pH 9.5) are evaluated], antigen retrieval methods (heated steam and proteinase K pre-digestion are evaluated), and antibody dilution. Conditions may be further altered as needed in consultation with BLS. High-throughput automated IHC platforms are used to maintain uniformity of staining between slides.