Additional file 4. Comparison of different CRT preparations from S. cerevisiae. Four different preparations (A, B, C, D) of purified human CRT from S. cerevisiae were analysed by SDS-PAGE (at the left) and Western blotting (at the right) using monoclonal antibodies against human CRT. M—prestained protein ladder (ThermoScientific, cat. no. 26616).