Antigens and antibodies

Recombinant Ebola virus glycoprotein with the mucin-like domain deleted (GP_Δmuc), and HIV-1 fusion peptide probe (VRC34-epitope scaffold-FP) and knock-out scaffold probe (VRC34-epitope scaffold-KO) were produced as described previously^19,31,32. Proteins were biotinylated and conjugated with streptavidin-APC (GP_Δmuc and VRC34-epitope scaffold-FP) or streptavidin-PE (VRC34-epitope scaffold-KO) (Thermo Fisher Scientific), respectively. Recombinant hemagglutinins (A/California/07/2009, A/Solomon Islands/3/2006, and A/Wisconsin/67/2005) were produced as before³³ or acquired from BEI Resources (A/Victoria/210/2009, and B/Brisbane/60/2008) and were biotinylated using an EZ-Link Sulfo-NHS-LC-Biotin kit (Thermo Fisher Scientific). Anti-flag FITC antibody was purchased from Sigma-Aldrich (clone M2).