Cyclin-dependent kinase 1, also known as CDK1, plays a key role in the control of the eukaryotic cell cycle by modulating the centrosome cycle as well as mitotic onset; promotes G2-M transition, and regulates G1 progress and G1-S transition via association with multiple interphase cyclins. This protein is required in higher cells for entry into S-phase and mitosis. Recombinant human CDK1 protein, fused to His-tag at C-terminus, was expressed in insect cells using baculovirus expression system and purified by using conventional chromatography techniques.