Reducing 2-DGE of sweet whey fraction from heat-treated milk visualised by colloid Coomassie Brilliant Blue G-250 staining. The conditions of the 2-DGE were as described in Figure 1 legend, except that this gel was run at reducing conditions as described in Materials and Methods. The positions of protein spots referred to in Table IV are indicated by an arrow and by their identification number in the image analysis of the reduced gels. The positions of major whey proteins assigned according to [31] are indicated in white. FABP, fatty acid binding protein; IgG HC, immunoglobulin G heavy chain; IgG LC, immunoglobulin G light chain; NPC2, Niemann Pick type 2 protein/EPV20; BSA, bovine serum albumin; and PP3, proteose peptone component 3.