Antibody-Driven Proximity Labeling in Fixed Tissues

: Protein function often depends on assemblies and interactions. These show complex spatial and temporal organization within the cell. Analysis of protein function can be greatly assisted by grouping proteins with their neighbors. Rather than relying on affinity, proximity labeling targets proteins proximal to the target of interest. We describe a protocol for antibody-guided deposition of tags in fixed and permeabilized cell lines and primary human tissue samples.