Secretion of human BiP protein into the yeast growth medium. SDS-PAGE (A) and Western blot against human BiP protein (B) of crude growth medium (40× concentrated) of yeast cells carrying control vector pFDC or pFDC-BiP for expression of human BiP. Cells were incubated for 36 h in YEPD medium. M – prestained molecular ladder (ThermoScientific, cat. no. 26618).