Streptavidin conjugate of peroxidase

For immunohistochemical detection, deparaffinized and rehydrated sections were used. Pretreatment in microwave 3 × 5 min at 800 W in the sodium citrate buffer (pH 6.0) and washing in 0.01 M PBS was mostly performed. For detection of polyglutamine deposits the pretreatment with 98% formic acid (5 min at room temperature) was required. Incubation in blocking solution (water solution of H₂O₂) for 20 min was followed by incubation with primary antibodies (Table 1) performed overnight at 4°C. Sections were then washed and incubated with the appropriate biotinylated secondary antibody (Jackson ImmunoResearch Lab., USA, 1 : 500) for 45 min at room temperature and subsequently with a streptavidin conjugate of peroxidase (Dako, CR) also for 45 min. Visualization of bound antibody was performed using DAB (Sigma-Aldrich, CR) and H₂O₂.