Fig. 2

Surface display and secretion of Fab-AH3/E3 in diploid Y-AH3/E3. a. The galactose induced yeast cells were harvested and stained to detect Fab display by FACS. The cells were incubated with mouse anti-HA and goat anti-human kappa followed by secondary labeling with donkey anti-mouse Dylight 550 and donkey anti-goat AF 488. The non-induced cells were used as a negative control. b. Neutralization assay with secretion culture supernatant. The yeast cells were induced to secrete Fab in SD medium containing 1% or 2% glucose at 30 °C for 72 h. The supernatants were diluted 4 times and co-cultured with Vero cells in the presence of 50 ng/mL TcdA or 10 pg/mL TcdB at 37 °C overnight. The images were taken using a phase-contrast microscope