Figure 3
Esculin uptake by yeast cells expressing StSUT1 was detected using FACS. Yeast cells (SEY6210) were incubated in 1 mM esculin in 25 mM Na-phosphate buffer (pH 4) for 3 hr at 30°C with shaking. Cells were collected by centrifugation, washed with 25 mM Na-phosphate buffer (pH 4.0) and resuspended with the same buffer at a density of 107 cells/ml. Cells were identified based on forward scatter (relative cell size) vs. esculin intensity. Fluorescent cells were detected by flow cytometry using a BD Biosciences FACSVantage DiVa sorter with a UV laser, excitation 355 nm, and a 450/50 detection filter (A) pDR196 vector control; (B) StSUT1 in pDR196); (C) OsSUT1 in pDR196).