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

Wu, Y, Gao, G and Gao, F(2021). Protein expression and purification. Bio-protocol Preprint. bio-protocol.org/prep878.
Wu, Y., Wang, F., Shen, C., Peng, W., Li, D., Zhao, C., Li, Z., Li, S., Bi, Y., Yang, Y., Gong, Y., Xiao, H., Fan, Z., Tan, S., Wu, G., Tan, W., Lu, X., Fan, C., Wang, Q., Liu, Y., Zhang, C., Qi, J., Gao, G. F., Gao, F. and Liu, L.(2020). A noncompeting pair of human neutralizing antibodies block COVID-19 virus binding to its receptor ACE2 . Science 368(6496). DOI: 10.1126/science.abc2241