FIGURE 6 from Sequential Chromogenic IHC: Spatial Analysis of Lymph Nodes Identifies Contact Interactions between Plasmacytoid Dendritic Cells and Plasmablasts

Citrate stripping is necessary before EDTA-based antigen retrieval. A patient sample was stained with CD68 in cycle 11 round 2 (A). In the next cycle, an EDTA antigen retrieval buffer was used to detect BCL6, without citrate stripping. Carryover from the previous cycle was observed by treatment with AEC and visualization (B). Stripping with a citrate antigen retrieval buffer was performed and EDTA-based antigen retrieval was conducted again, which allowed to visualize BCL6 without carryover from previous staining (C). Note the different morphology of BCL6+ and CD68⁺ cells within the same region (A, C). Same section is shown in A–C. Scale bar: 100 μm (10X).