Premium grade sa pe

PfPfMSP1, PfPfAMA1 and TT were biotinylated with the Sulfo-NHS-LC-Biotinylation Kit (ThermoFisher) at a ratio of 1:1 according to the manufacturer’s instructions. For detection of PfCSP-specific cells biotinylated (NANP)₉ peptide was sourced from Biomatik (Ontario, Canada). Biotinylated Ags were incubated with premium-grade SA-PE and SA-APC (Molecular Probes) at a molar ratio of 4:1, added four times with 15 min incubation at room temperature.
PBMCs, processed and cryopreserved at 5 × 10⁶ [31 (link)], were thawed and washed in PBS with 2% heat inactivated FBS. Approximately 2.5 × 10⁶ cells were incubated with 1 μL of both SA-PE and SA-APC tetramers for 20 min at room temperature. Cells were further incubated for an additional 30 min with human B-cell surface molecules using the antibodies listed in Supporting Information Table 2. One million events were acquired on a BD Fortessa flow cytometer (BD Biosciences, San Jose, CA) and the data analysed using FlowJo software (Tree Star, Inc, Ashland, OR).