To test the method specificity in the procedures for histoblotting, as well as for both light and electron microscopy, antisera against GIRK1, GIRK2 and GIRK3 were tested on brain slices of mice lacking the corresponding channel subunit (Supporting Information Fig. S3) (Aguado et al., 2008; Fernández-Alacid et al., 2009). Furthermore, the primary antibody was either omitted or replaced with 5% (v/v) normal serum of the species of the primary antibody. Under these conditions, no selective labelling was observed.
