Figure 2. Titration of reagents for biotin-labeling and SA-ZZ immobilization on yeast cells.

Respective indirect fluorescence signals were analyzed by flow cytometry. (A) 1×10⁷ cells were labeled with 1 mg to 6 mg biotin reagent and stained with streptavidin-Dylight633. (B) 1×10⁷ cells labeled with 1 mg biotin were incubated with 2, 3 or 4 µg of SA-ZZ for immobilization of the Fc-capture moiety. Subsequently surface ZZ domain was detected using a FITC-conjugated goat-anti-protein A antibody.