An Optimized Immunohistochemical Protocol for Both Manual and Automated Staining of Formalin Fixed, Paraffin Embedded Human Placenta for Demonstration and Analyses of FAS, FAS-L, and Bcl-2

Abstract An immunohistochemical staining protocol for 3 antibodies, FAS (APO-1, CD95), its ligand FAS-L (cell death factors), and Bcl-2 (cell death blocker), for use specifically on the immunologically privileged (and immunohistochemically difficult) tissue, placenta, has been developed. This represents, to our knowledge, the first reported successful optimization of Fas, Fas-L and Bcl-2 for use in formalin fixed, paraffin embedded placental tissue. Optimized staining proved amenable to both manual and automated protocols. The system is both time-efficient and cost effective and should facilitate investigation into the role played by these molecules in immune privilege. Application of a standardized technique lends power to inter-laboratory, bio-medical studies requiring objective, quantitative immunohistochemical analyses. (The J Histotechnol 21:285–293, 1998)