Citrate buffer pH 6.0. Slides were left to cool down in the antigen retrieval solution for 20 minutes. Endogenous peroxidase activity was quenched by first incubating the specimens for 5 min in 3 hydrogen peroxide (supplied by user). The specimens were then incubated with the primary antibody against Apo-J (clone sc-6420, goat polyclonal antibody, Santa Cruz Biotechnology Inc, CA) in a dilution 1