Fig. 2. A strategy for the purification of CDK complexes.

Sf9 cells were co-infected with the baculoviruses expressing cyclin dependent kinases and their corresponding cyclin partners. Cell extract was loaded on Ni²⁺-NTA beads and eluted with stepwise imidazole gradients. Fractions containing the recombinant kinases were pooled, buffer exchanged on PD10 column and loaded on Mono S beads and purified by a linear 0.08-0.5 M NaCl gradient.