“…The percentage of yeast cells binding to the anti-Xpress antibody (Thermo Fisher Scientific, Waltham, MA, USA), conformation-sensitive anti-human CH2 antibody (Bio-Rad, Hercules, CA, USA), protein A (Sigma-Aldrich, St. Louis, MO, USA) and CD64 (R&D Systems, Minneapolis, Minnesota, USA) was determined as described before [50]. The first antigen selection round proceeded with magnetic activated cell sorting (MACS) as described previously [52], using 1 µM biotinylated CD59, refolded from bacterial inclusion bodies, and further sorting rounds were performed with yeast cells stained with 1 µM biotinylated CD59 and a fluorescein isothiocyanate (FITC)-conjugated anti-human CH2 antibody (Bio-Rad, Hercules, CA, USA), diluted 1:200 in 10% bovine serum albumin (BSA)-PBS. Bound CD59 was detected using the conjugated streptavidin-Alexa Fluor ® 647 or NeutrAvidin ® -phycoerythrin (PE) (both Thermo Fisher Scientific, Waltham, MA, USA), diluted 1:1000, interchangeably in the sorting rounds.…”