Readers should cite both the Bio-protocol preprint and the original research article where this protocol was used:

Brenna, A and Albrecht, U(2020). In vitro kinase assay using immunoprecipitated Cdk5 from SCN. Bio-protocol Preprint. bio-protocol.org/prep216.
Brenna, A., Olejniczak, I., Chavan, R., Ripperger, J. A., Langmesser, S., Cameroni, E., Hu, Z., De Virgilio, C., Dengjel, J. and Albrecht, U.(2019). Cyclin-dependent kinase 5 (CDK5) regulates the circadian clock. eLIFE. DOI: 10.7554/eLife.50925