Figure 4.

Suppressing the nonspecific cross-immunoreactivity and improving specific immunostaining in aged human brain tissues. A and D: with regular immunostaining protocol, nonspecific staining with anti-rabbit secondary antibody (A) or phospho-tau at Thr231 (D, pT231) was detected. The nonspecific staining confused with specific pT231 immunostaining (D). With modified protocols either by using a secondary antibody buffer containing 0.5% Tween-20 (B and E) or tissue pretreatment with 1% sodium borohydride (C and F), little cross-immunoreactivity was detected with anti-rabbit secondary antibody alone (B, C), and phospho-tau immunostaining showed clear and specific pT231 immunoreactivity with less background (E, F). Scale Bar 30 μm.