Recombinant human WEE1 (WEE1 G2 checkpoint kinase), encompassing amino acids 215-646 (end). In this construct the N-terminal end of WEE1 is fused with GST. A short peptide linker placed between GST and the protein includes a thrombin cleavage site to facilitate removal of the GST portion. The recombinant protein was affinity purified.