Hi Lin,  I used the Dako antibody to Ki-67 with this protocol on FFPE mouse
tissue. Best of luck.

HIER   citrate 0.01M   pH 6.0    microwave 5 min.
10% NGS 15 min
Ki-67  1:20 in PBS  30 min RT
GAR, bio, 1:50  Zymed 62-9540
ABC, Vector elite kit, 30 min RT
NovaRed chromogen 2 min RT