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

An immunohistochemical staining protocol for 3 antibodies, FAS (APO-1, CD95 ), its ligand FAS-L (cell death factors), and Bcl-2 (cell death blocker), f or use specifically on the immunologically privileged (and immunohistochemi cally 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. Optim ized staining proved amenable to both manual and automated protocols. The s ystem is both time-efficient and cost effective and should facilitate inves tigation into the role played by these molecules in immune privilege. Appli cation of a standardized technique lends power to inter-laboratory, bio-med ical studies requiring objective, quantitative immunohistochemical analyses .