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

Cantuti-Castelvetri, L, Teesalu, T, Balistreri, G and Simons, M(2022). Antibody labeling and binding assay with b1b2 domain of NRP-1. Bio-protocol Preprint. bio-protocol.org/prep2017.
Cantuti-Castelvetri, L., Ojha, R., Pedro, L. D., Djannatian, M., Franz, J., Kuivanen, S., Meer, F. V. D., Kallio, K., Kaya, T., Anastasina, M., Smura, T., Levanov, L., Szirovicza, L., Tobi, A., Kallio-Kokko, H., Österlund, P., Joensuu, M., Meunier, F. A., Butcher, S. J., Winkler, M. S., Mollenhauer, B., Helenius, A., Gokce, O., Teesalu, T., Hepojoki, J., Vapalahti, O., Stadelmann, C., Balistreri, G. and Simons, M.(2020). Neuropilin-1 facilitates SARS-CoV-2 cell entry and infectivity. Science 370(6518). DOI: 10.1126/science.abd2985