Protocol for proximity ligation assay combined with immunolabeling of paraffin-embedded lung tissue in a porcine model.

Protein-protein interaction (PPI) studies are essential for understanding cellular communication, and identifying the specific cell types in which these interactions occur is critical. Here, we present a protocol for detecting protein proximities in a porcine model using the proximity ligation assay (PLA) combined with immunolabeling to assign signals to defined cell populations. We describe the steps for slide preparation, including deparaffinization, heat-induced epitope retrieval (HIER), permeabilization, blocking of sites, and incubation with primary antibodies. We also detail the procedures for combining the PLA method with immunolabeling. For complete details on the use and execution of this protocol, please refer to Cousin et al.