Cdk1 antibody

CDK1 expression was determined with the CDK1 antibody (1:100, Abcam, USA). Xylene and alcohol were used for dewaxing, 3% H₂O₂ was used to remove endogenous catalase, and citrate buffer was added; the sample was placed in a microwave oven and cooked to expose the antigen site, after which serum blocking was performed. After incubation, the antibody and the secondary antibody were used to develop the color, and the samples were mounted. Each tissue section was rated using a light microscope based on the staining level (0, 1, 2, and 3 indicated negative, yellowish, light brown, and dark brown staining, respectively) and the extent of positivity (1, 2, 3, and 4 represented 0–25%, 26–50%, 51–75%, and 76–100%, respectively). Finally, the scores were added for comparison. All IHC sections were evaluated independently by two expert pathologists.

Kinase assays were performed using a previously described protocol [55] (link). Briefly, CDK1 was immunoprecipitated from equal amounts of infected or drug-treated A9 cell lysates using 4 µg of CDK1 antibody (Cat # Ab18, Abcam). Histone H1 (Millipore) was used as a substrate for kinase assays.