The protein expression of aurora-A and aurora-B kinase in canine mast cell tumor cell lines (CoMS, CM-MC1 and VI-MC1). Canine aortic endothelial cells served as a positive control. The aurora-A and aurora-B kinases were detected in all three canine malignant mast cell tumor cell lines. There is cross reactivity between the aurora-A and aurora-B antibodies. The protein size of aurora-A, aurora-B, and GAPDH are approximately 48, 39, and 37 KD, respectively. GAPDH was used as a loading control, and the intensity of bands of GAPDH in all three mast cell tumor cell lines are identical. Cn, ARK-A, and ARK-B represent canine aortic endothelial cells, aurora-A kinase and aurora-B kinase, respectively.