Metal-Conjugated Antibody Staining for MIBI

Antibodies were first screened by IHC on FFPE brain sections to select for the best clones. These were then conjugated to isotopic metal reporters as described previously^{40 (link),44 (link)}. Following conjugation antibodies were diluted in Candor PBS Antibody Stabilization solution (Candor Bioscience). Antibodies were either stored at 4°C or lyophilized in 100 mM D-(+)-Trehalose dehydrate (Sigma-Aldrich) with ultrapure distilled H2O for storage at −20°C. Before staining, lyophilized antibodies were reconstituted in a buffer of Tris (Thermo Fisher Scientific), sodium azide (Sigma-Aldrich), ultrapure water (Thermo Fisher Scientific) and antibody stabilizer (Candor Bioscience) to a concentration of 0.05 mg ml⁻¹. The antibodies, metal reporters and staining concentrations are listed in Extended Data Table S1. For detailed metal-antibody protocol MIBItag see dx.doi.org/10.17504/protocols.io.bhyej7te.