Fig. (4) Identification of T3SS Interactions in situ Using Protein Microarrays. (A) Scheme used to identify protein-protein interaction using HaloTag recombinant proteins and His-MBP tagged recombinant proteins. (B) Immobilized His-MBP tagged T3SSs on Cu2+/IDA/PEG were visualized with anti-His-tag antibody (left) and interacting proteins with IcrG were detected by the rabbit anti-Halo antibody and goat anti-rabbit antibody labeled with Alexa555 (right).