Absolute quantitation of binding antibodies from clinical samples.

"Competing interests All authors are/were employees of Janssen when this work was performed and may hold Johnson & Johnson stock or stock options. J.S., A.V., D.J.S., E.S.-V., and T.vdK. are named inventors on a pending patent application for the methodology described (WO2022180212A)."

"This study was funded by Janssen Vaccines & Prevention. The authors would like to thank Sharitee Bouthisma, Liesbeth Vereyken, and Edgar Rodriguez for technical assistance in sample preparation, mass spectrometry analysis and data processing, and Sanne Roels, Guangjian Fu, and Bin Yu for statistical data analysis. We are grateful to Pascale Bouchier, Annemart Koornneef, Ava Sadi, and Sven Blokland for assistance in selecting and characterizing HIV-1 Env proteins and in producing monoclonal HIV-1 Env-specific antibodies. We thank Maria Grazia Pau, Valerie Oriol Mathieu, Victor Beslier, Janine van Duijn, Frederik Broszeit, Veronica Rezelj, and Anna Ohanjanyan for helpful discussions and critical review of the manuscript. We gratefully acknowledge project management support from Lidia Roman Gonzalez and Yvonne Salzgeber."