Double immunofluorescence staining for interleukin-6 receptor (IL-6R) and glutamine synthase (GS). Representative sections through lumbar dorsal root ganglia (DRG) incubated (A) with rabbit polyclonal anti-IL-6R and then (B) with mouse monoclonal anti-GS antibodies. To visualize colocalization, the section was treated with affinity-purified secondary antibodies: tetramethyl rhodamine isothiocyanate (TRITC)-conjugated donkey anti-rabbit and fluorescein isothiocyanate (FITC)-conjugated donkey anti-mouse. Staining with Hoechst 33342 was used to detect positions of the cell nuclei. (C) Merged picture shows increased immunofluorescence staining for IL-6R in satellite glial cells (SGC), indicated by simultaneous immunostaining for GS (arrowheads). Sections were cut through ipsilateral lumbar DRG of rats 3 days after unilateral chronic constriction injury (CCI) of the sciatic nerve. Scale bars = 40 μm.