Complex of human CDK1 (cyclin-dependent kinase 1) and human cyclin B1 (CCNB1). The proteins were co-expressed in Sf9 insect cells. Recombinant human CDK1, full length encompassing amino acids 2-297(end), contains an N-terminal GST-tag followed by a PreScission Protease Cleavage Site. Recombinant human cyclin B1, full length encompassing amino acids 2-433(end), contains an N-terminal GST-tag followed by a PreScission Protease Cleavage Site. The recombinant proteins were affinity purified.